my_dict = {"color": "red", "width": 17, "height": 19}
value_to_find = "red"

# Brute force solution (fastest) -- single key
for key, value in my_dict.items():
    if value == value_to_find:
        print(f'{key}: {value}')
        break

# Brute force solution -- multiple keys
for key, value in my_dict.items():
    if value == value_to_find:
        print(f'{key}: {value}')

# Generator expression -- single key
key = next(key for key, value in my_dict.items() if value == value_to_find)
print(f'{key}: {value_to_find}')

# Generator expression -- multiple keys
exp = (key for key, value in my_dict.items() if value == value_to_find)
for key in exp:
    print(f'{key}: {value}')

# Inverse dictionary solution -- single key
my_inverted_dict = {value: key for key, value in my_dict.items()}
print(f'{my_inverted_dict[value_to_find]}: {value_to_find}')

# Inverse dictionary solution (slowest) -- multiple keys
my_inverted_dict = dict()
for key, value in my_dict.items():
    my_inverted_dict.setdefault(value, list()).append(key)
print(f'{my_inverted_dict[value_to_find]}: {value_to_find}')

my_dict = {
  'Izuku Midoriya': 'One for All', 
  'Katsuki Bakugo': 'Explosion', 
  'All Might': 'One for All', 
  'Ochaco Uraraka': 'Zero Gravity'
}

# Use to invert dictionaries that have unique values
my_inverted_dict = dict(map(reversed, my_dict.items()))

# Use to invert dictionaries that have unique values
my_inverted_dict = {value: key for key, value in my_dict.items()}

# Use to invert dictionaries that have non-unique values
from collections import defaultdict
my_inverted_dict = defaultdict(list)
{my_inverted_dict[v].append(k) for k, v in my_dict.items()}

# Use to invert dictionaries that have non-unique values
my_inverted_dict = dict()
for key, value in my_dict.items():
    my_inverted_dict.setdefault(value, list()).append(key)

# Use to invert dictionaries that have lists of values
my_dict = {value: key for key in my_inverted_dict for value in my_inverted_dict[key]}

yusuke_power = {"Yusuke Urameshi": "Spirit Gun"}
hiei_power = {"Hiei": "Jagan Eye"}
powers = dict()

# Brute force
for dictionary in (yusuke_power, hiei_power):
    for key, value in dictionary.items():
        powers[key] = value

# Dictionary Comprehension
powers = {key: value for d in (yusuke_power, hiei_power) for key, value in d.items()}

# Copy and update
powers = yusuke_power.copy()
powers.update(hiei_power)

# Dictionary unpacking (Python 3.5+)
powers = {**yusuke_power, **hiei_power}

# Backwards compatible function for any number of dicts
def merge_dicts(*dicts: dict):
    merged_dict = dict()
    for dictionary in dicts:
        merge_dict.update(dictionary)
    return merged_dict

# Dictionary union operator (Python 3.9+ maybe?)
powers = yusuke_power | hiei_power

virtualenv env

# linux
source env/bin/activate

#windows
env\Scripts\activate.bat

deactivate

from flask import Flask,render_template,request, redirect
 
 
app = Flask(__name__)
app.config['SECRET_KEY'] = 'dajdsjas'
 
 
@app.route('/home')
def home():
    return 'Home page'
 
 
 
@app.route('/take_parameter', methods = ["POST"])
def takeparam():
    try:
        pas = request.args(silent=True)
        #app.logger.info(json)
        return 'OK'
    except:
        return 'INTERNAL ERROR', 500
    
 
@app.route('/take_json', methods = ["POST"])
def takejson():
    try:
        pas = request.get_json(silent=True)
        #app.logger.info(json)
        return 'OK'
    except:
        return 'INTERNAL ERROR', 500
    
if __name__ =='__main__':
    app.run(debug=True)
 

# Works with matplotlib and seaborn

%config InlineBackend.figure_format ='retina'

%whos

from IPython.core.interactiveshell import InteractiveShell
InteractiveShell.ast_node_interactivity = "all"

from itertools import zip_longest
l1=[1,2,3,4,5,6,7]
l2=['a','b','c','d']
d1=zip_longest(l1,l2,fillvalue='x')
print (d1)#Output:<itertools.zip_longest object at 0x00993C08>
#Converting zip object to dict using dict() contructor.
print (dict(d1))
#Output:{1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'x', 6: 'x', 7: 'x'}

df = df[["C", "A", "B"]]

from time import strptime
month_name = 'Jan'
month_number = strptime(month_name, '%b').tm_mon
month_number

'''
%a  Locale’s abbreviated weekday name.    
%A  Locale’s full weekday name.    
%b  Locale’s abbreviated month name.  
%B  Locale’s full month name.      
%c  Locale’s appropriate date and time representation.    
%d  Day of the month as a decimal number [01,31].    
%f  Microsecond as a decimal number [0,999999], zero-padded on the left     (1)
%H  Hour (24-hour clock) as a decimal number [00,23].    
%I  Hour (12-hour clock) as a decimal number [01,12].    
%j  Day of the year as a decimal number [001,366].  
%m  Month as a decimal number [01,12].  
%M  Minute as a decimal number [00,59].      
%p  Locale’s equivalent of either AM or PM.   (2)
%S  Second as a decimal number [00,61].     (3)
%U  Week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Sunday are considered to be in week 0.    (4)
%w  Weekday as a decimal number [0(Sunday),6].  
%W  Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0.    (4)
%x  Locale’s appropriate date representation.      
%X  Locale’s appropriate time representation.      
%y  Year without century as a decimal number [00,99].    
%Y  Year with century as a decimal number.  
%z  UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).    (5)
%Z  Time zone name (empty string if the object is naive).    
%%  A literal '%' character.
'''

>>> mydict = {'one': [1,2,3], 2: [4,5,6,7], 3: 8}

>>> dict_df = pd.DataFrame({ key:pd.Series(value) for key, value in mydict.items() })

>>> dict_df

   one  2    3
0  1.0  4  8.0
1  2.0  5  NaN
2  3.0  6  NaN
3  NaN  7  NaN

import re 
s = "string. With. Punctuation?" 
s = re.sub(r'[^\w\s]','',s) 

import os  
path="abc.txt"  
if os.path.isdir(path):  
    print("\nIt is a directory")  
elif os.path.isfile(path):  
    print("\nIt is a normal file")  
else:  
    print("It is a special file (socket, FIFO, device file)" )
print()

df['column_name'] = pd.to_datetime(df['column_name'])
# new version
df.groupby(pd.Grouper(key='column_name', freq="M")).mean().plot()

start_time = time.clock()
result = 0
for row in df.itertuples(index=False):
    result += max(row[df.columns.get_loc('B')], row[df.columns.get_loc('C')])

total_elapsed_time = round(time.clock() - start_time, 2)
print("4. Polyvalent Itertuples working even with special characters in the column name done in {} seconds, result = {}".format(total_elapsed_time, result))

import pkg_resources, string
from symspellpy import SymSpell, Verbosity

spell = SymSpell(max_dictionary_edit_distance=2, prefix_length=7)
dictionary_path = pkg_resources.resource_filename('symspellpy', 'frequency_dictionary_en_82_765.txt')
spell.load_dictionary(dictionary_path, term_index=0, count_index=1)

def correct(w):
  word = w
  o = spell.lookup(w,
    Verbosity.CLOSEST,
    max_edit_distance=2,
    transfer_casing=True)
  if not o: return w
  word = o[0].term
  if w[0].isupper():
    word = word[0].upper() + ''.join(word[1:])
  # find start punctuation
  start_idx = 0
  start_punct = ''
  while w[start_idx] in string.punctuation:
    start_punct += w[start_idx]
    if start_idx + 1 < len(w):
      start_idx += 1
    else:
      break
  # find end punctuation
  end_idx = 1
  end_punct = ''
  while w[-end_idx] in string.punctuation:
    end_punct += w[-end_idx]
    if end_idx - 1 > 0:
      end_idx -= 1
    else:
      break
  return start_punct + word + end_punct

s = '''Now that we have carried our geographical analogy quite far, we return to the uestion of isomorphisms between brains. You might well wonder why this whole uestion of brain isomorphisms has been stressed so much. What does it matter if two rains are isomorphic, or quasi-isomorphic, or not isomorphic at all? The answer is that e have an intuitive sense that, although other people differ from us in important ways, hey are still "the same" as we are in some deep and important ways. It would be nstructive to be able to pinpoint what this invariant core of human intelligence is, and hen to be able to describe the kinds of "embellishments" which can be added to it, aking each one of us a unique embodiment of this abstract and mysterious quality alled "intelligence".'''
cleaned = ' '.join([correct(w) for w in s.split()])
print(cleaned)

phrase = input("Choose your phrase:")
def translate(phrase):
    for letter in phrase:
        if letter in "C":
            letter = phrase.replace("C","b")
        if letter in "c":
            letter = phrase.replace("c","b")
        else:
            letter = phrase
        return letter
print(translate(phrase))

def getFactorialit (n):
	if n < 0, return -1
    else fact = 1
    for i in range (1, n +1):
    	fact *=i
    return fact
    
print getFactorialit(10)
    

desired_tab = driver.current_window_handle  #storing the handle in a variable
if driver.current_window_handle != desired_tab:
   driver.switch_to_window(desired_tab)  #switching to the tab in case it's not

my_classifiers = {'logit': '<trained_logit_here>',
                  'KNN' : '<trained_KNN_here>'
                  }
pickle._dump(my_classifiers, open(filename, 'wb'))

loaded_classifiers = pickle.load(open(filename, 'rb'))
logit_model = loaded_classifiers['logit']
knn_model = loaded_classifiers['KNN']

results = logit_model.predict(X)

x = tf.placeholder(tf.int16, shape=(), name='ha')
y = tf.placeholder(tf.int16, shape=(), name='ho')

add = tf.add(x, y)
mul = tf.multiply(x, y)

# creates a list of numbers

numbers = ['1','2','3','4','5','6','7','8','9','0'] 

# a function that removes the string characters such as "$" or "," by using the list created above

def convertToInt(column):
    return int(''.join(filter(lambda x: x in numbers, column)))

.groupby(['node1','node2'])

import datetime
import dateutil.relativedelta

d = datetime.datetime.strptime("2013-03-31", "%Y-%m-%d")
d2 = d - dateutil.relativedelta.relativedelta(months=1)
print d2

from pyspark.sql import SparkSession
spark = SparkSession.builder.appName('abc').getOrCreate()

import datetime

def last_day_of_month(any_day):
    next_month = any_day.replace(day=28) + datetime.timedelta(days=4)  # this will never fail
    return next_month - datetime.timedelta(days=next_month.day)

from datetime import datetime, timedelta

d = datetime.today() - timedelta(days=days_to_subtract)

>>> from enum import Enum
>>> class Build(Enum):
...   debug = 200
...   build = 400
... 

Build['debug']

df.set_index(KEY).to_dict()[VALUE]

3 ways:
dict(zip(df.A,df.B))
pd.Series(df.A.values,index=df.B).to_dict()
df.set_index('A').to_dict()['B']

def isfloat(value):
  try:
    float(value)
    return True
  except ValueError:
    return False

df = df[df['EPS'].notna()]

f = open('test.json')
json_file = json.load(f)

df = df[df['EPS'].notna()]

import pandas as pd

data_dict = {'one': pd.Series([1, 2, 3], index=['a', 'b', 'c']),
             'two': pd.Series([1, 2, 3, 4], index=['a', 'b', 'c', 'd'])}

df = pd.DataFrame(data_dict)

print(f"DataFrame:\n{df}\n")
print(f"column types:\n{df.dtypes}")

col_one_list = df['one'].tolist()

col_one_arr = df['one'].to_numpy()

print(f"\ncol_one_list:\n{col_one_list}\ntype:{type(col_one_list)}")
print(f"\ncol_one_arr:\n{col_one_arr}\ntype:{type(col_one_arr)}")

df = pd.DataFrame([
    [-0.532681, 'foo', 0],
    [1.490752, 'bar', 1],
    [-1.387326, 'foo', 2],
    [0.814772, 'baz', ' '],     
    [-0.222552, '   ', 4],
    [-1.176781,  'qux', '  '],         
], columns='A B C'.split(), index=pd.date_range('2000-01-01','2000-01-06'))

# replace field that's entirely space (or empty) with NaN
print(df.replace(r'^\s*$', np.nan, regex=True))

df = pd.DataFrame([
    [-0.532681, 'foo', 0],
    [1.490752, 'bar', 1],
    [-1.387326, 'foo', 2],
    [0.814772, 'baz', ' '],     
    [-0.222552, '   ', 4],
    [-1.176781,  'qux', '  '],         
], columns='A B C'.split(), index=pd.date_range('2000-01-01','2000-01-06'))

# replace field that's entirely space (or empty) with NaN
print(df.replace(r'^\s*$', np.nan, regex=True))

df.replace(to_replace = 0.0, value = -1, inplace = True)

nov_mask = df['Dates'].map(lambda x: x.month) == 11
df[nov_mask]

nov_mar_series = pd.Series(pd.date_range("2013-11-15", "2014-03-15"))
#create timestamp without year
nov_mar_no_year = nov_mar_series.map(lambda x: x.strftime("%m-%d"))
#add a yearless timestamp to the dataframe
df["no_year"] = df['Date'].map(lambda x: x.strftime("%m-%d"))
no_year_mask = df['no_year'].isin(nov_mar_no_year)
df[no_year_mask]

from redis.sentinel import Sentinel
sentinel = Sentinel([
    ('192.168.77.130',26379),
    ('192.168.77.130',26380),
    ('192.168.77.130',26381),
],sentinel_kwargs={'password': '123456'}) 

sentinel.discover_master('lerep')

 # single column:
 if `A` in df and `B` in df:
 
 
 # multiple columns:
 pd.Series(['A', 'B']).isin(df.columns).all()

import re
if re.match(r"hello[0-9]+", 'hello1'):
    print('Yes')

import pandas as pd
from datetime import datetime

ps = pd.Series([datetime(2014, 1, 7), datetime(2014, 3, 13), datetime(2014, 6, 12)])
new = ps.apply(lambda dt: dt.replace(day=1))

all_data['Order Day new'] = all_data['Order Day new'].dt.strftime('%Y-%m-%d')

def ffill_cols(df, cols_to_fill_name='Unn'):
    """
    Forward fills column names. Propagate last valid column name forward to next invalid column. Works similarly to pandas
    ffill().
    
    :param df: pandas Dataframe; Dataframe
    :param cols_to_fill_name: str; The name of the columns you would like forward filled. Default is 'Unn' as
    the default name pandas gives unnamed columns is 'Unnamed'
    
    :returns: list; List of new column names
    """
    cols = df.columns.to_list()
    for i, j in enumerate(cols):
        if j.startswith(cols_to_fill_name):
            cols[i] = cols[i-1]
    return cols

>>> from operator import add
>>> list( map(add, list1, list2) )
[5, 7, 9]

class Parent(object):
      def implicit(self):
          print("PARENT implicit()")

class Child(Parent):
      pass
    dad = Parent()
    son = Child()
    
    dad.implicit()
    son.implicit()

x=[]
y=[]
for key, value in genres.items():
    x.append(key)
    y.append(value)

for key in sorted(my_dict, key=my_dict.get):

    print('{} : {}'.format(key, my_dict[key]))

from csv import reader
fp = open('file_name.csv', encoding='utf-8')
data = list(reader(fp))
fp.close()

>>> matches = re.findall(f'(?:{p})+', s)
>>> matches
['HELLO', 'HELLO', 'HELLOHELLOHELLO', 'HELLOHELLO']

>> max(map(len, matches)) // len(p)
3

from setuptools import setup, find_packages

setup(
  name="package-name",
  version="0.0.0",
  packages=find_packages(),
  entry_points = {
    'console_scripts':
      ["command = package_name.module_name:function_name"],
    },
)

and
or
not
!=(not equal)
==(equal)
>=(greater-than-equal)
<=(less-than-equal)
True
False

>>> format(integer, '0>42b')
'001010101111000001001000111110111111111111'

def mlm_loss(y_true, y_pred):
loss=float(0)
a = tf.keras.backend.constant(1, dtype='float32')
for s in range(batch_size): # for each sample in batch
    for i in range(L):
        for j in range(L):
            loss=loss + y_true[s][i]*(a-y_true[s][j])*(a-(y_pred[s][i]-y_pred[s][j])) #two conditions
l= tf.keras.backend.constant(L, dtype='float32')            
loss=a/l*loss           
return loss

def add(a, b):
    print(f"ADDING {a} + {b}")
    return a + b
  
def subtract(a, b):
    print(f"SUBTRACTING {a} - {b}")
    return a - b

# this is like your scripts with argv
def print_two(args):
    arg1, arg2 = args
    print(f"arg1:{arg1}, arg2: {arg2}")
 
# this just takes one argument
def print_one(arg1):
    print(f"arg1:{arg1}")
    
# this one takes no argument
def print_none():
     print?("I got nothin',")

from sys import argv
script, first, second = argv

print("The script is called:", script)
print("The first variable is:", first)
print("The second variable is:", second)

from sys import argv

script, filenames = argv

txt = open(filename)

print(f"Here's your life {filename}:")
print(txt.read())

print("Type the filename again:")
file_open = input(">")

txt_again = open(file_again)
print(txt_again.read())

print("How old are you?", end=' ')
age = input()
print("How tall are you?", end= ' ')
height = input()
print("How much do you weight?", end= ' ')
weight = input()

print(f"So, you're {age} old, {height} tall and {weight} heavy.")

from sys import argv
script, first, second

print("The script is called:", script)
print("your first variable is:", first)
print("your second variable is:, second)

formatter = "{} {} {} {}"

print(formatter.format(1, 2, 3, 4,))
print(formatter.format(one, two, three, four))
print(formatter.format(true, false, false, true))

end1 = "B"
end2 = "u"
end3 = "r"
end4 = "g"
end5 = "e"
end6 = "r"

print(end1 + end2 + end3 + end4 + end5)

A) Detect faces in Image file (using Python & OpenCV)



face_detect.py :
=================

import cv2

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

img = cv2.imread('face.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)


faces = face_cascade.detectMultiScale(
    gray,
    scaleFactor=1.1,
    minNeighbors=5,
    minSize=(30, 30),
    flags = cv2.CASCADE_SCALE_IMAGE
)

print("Faces shape : ", faces.shape)

for (x,y,w,h) in faces:
    cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)

print("Face count : ", faces.shape[0])

cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()


=====================================================================

B) Detect faces using Camera (using Python & OpenCV).


face_detect_cam.py :
====================
import cv2

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

cap = cv2.VideoCapture(0)

while True:
	ret, img = cap.read();
	
	if not ret:
		break
		
	gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

	faces = face_cascade.detectMultiScale(
		gray,
		scaleFactor=1.1,
		minNeighbors=5,
		minSize=(30, 30),
		flags = cv2.CASCADE_SCALE_IMAGE
	)

	for (x,y,w,h) in faces:
		cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
	
	cv2.imshow('Face', img)
	
	key = cv2.waitKey(1)
	if key==27 or key==ord('q'):
		break;

cap.release()
cv2.destroyAllWindows()

types_of_people = 10
x = f"there are {types_of_people} types of people."

binary = "binary"
do_not = don't
y = f"those who know {binary} and those who {do_not}."

cars = 80
drivers = 40
passengers = 70

Print(cars)

# print this line
print("Hello world again")

print("Hello world!")

# ...
plt.legend()
plt.savefig(f"{d['Country'].iat[0]}_plot.png")
# ...

In [1]: data = [
   ...:     {'id': '10', 'animal' : 'cat'},
   ...:     {'id': '11', 'animal' : 'dog'},
   ...:     {'id': '3', 'animal' : 'pigeon'},
   ...:     {'id': '10', 'color' : 'yellow'},
   ...:     {'id': '11', 'color' : 'brown'},
   ...:     {'id': '3', 'color' : 'grey'},
   ...:     {'id': '10', 'type' : 'furry'},
   ...:     {'id': '11', 'type' : 'fluffy'},
   ...:     {'id': '3', 'type' : 'dirty'},
   ...: ]

In [2]: from collections import defaultdict
   ...: ids = defaultdict(dict)
   ...: for d in data:
   ...:     ids[d["id"]].update(d)
   ...:


In [6]: list(ids.values())
Out[6]:
[{'id': '10', 'animal': 'cat', 'color': 'yellow', 'type': 'furry'},
 {'id': '11', 'animal': 'dog', 'color': 'brown', 'type': 'fluffy'},
 {'id': '3', 'animal': 'pigeon', 'color': 'grey', 'type': 'dirty'}]

d = dict.fromkeys(df.select_dtypes(object).columns, 0)
df = df.assign(**d)

class MyModel(models.Model):
        field1 = models.CharField(max_length=40, blank=False, null=False)
        field2 = models.CharField(max_length=60, blank=True, null=True)

# Open a file: file
file = open('my_text_file',mode='r')
 
# read all lines at once
all_of_it = file.read()
 
# close the file
file.close()

python -m http.server [<portNo>]

import ast
l = ast.literal_eval('[ "A","B","C" , " D"]')
l = [i.strip() for i in l]

from datetime import datetime, timedelta

d = datetime.today() - timedelta(days=days_to_subtract)

def toDate(dateString): 
    return datetime.datetime.strptime(dateString, "%Y-%m-%d").date()

@app.route()
def event():
    ektempo = request.args.get('start', default = datetime.date.today(), type = toDate)
    ...

from datetime import date
from dateutil.rrule import rrule, DAILY

a = date(2009, 5, 30)
b = date(2009, 6, 9)

for dt in rrule(DAILY, dtstart=a, until=b):
    print dt.strftime("%Y-%m-%d")

# result and path should be outside of the scope of find_path to persist values during recursive calls to the function
result = []
path = []
from copy import copy

# i is the index of the list that dict_obj is part of
def find_path(dict_obj,key,i=None):
    for k,v in dict_obj.items():
        # add key to path
        path.append(k)
        if isinstance(v,dict):
            # continue searching
            find_path(v, key,i)
        if isinstance(v,list):
            # search through list of dictionaries
            for i,item in enumerate(v):
                # add the index of list that item dict is part of, to path
                path.append(i)
                if isinstance(item,dict):
                    # continue searching in item dict
                    find_path(item, key,i)
                # if reached here, the last added index was incorrect, so removed
                path.pop()
        if k == key:
            # add path to our result
            result.append(copy(path))
        # remove the key added in the first line
        if path != []:
            path.pop()

# default starting index is set to None
find_path(di,"location")
print(result)
# [['queryResult', 'outputContexts', 4, 'parameters', 'DELIVERY_ADDRESS_VALUE', 'location'], ['originalDetectIntentRequest', 'payload', 'inputs', 0, 'arguments', 0, 'extension', 'location']]

>>> from sklearn.metrics import f1_score
>>> y_true = [0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 2, 1, 0, 0, 1]
>>> f1_score(y_true, y_pred, average='macro')
0.26...
>>> f1_score(y_true, y_pred, average='micro')
0.33...
>>> f1_score(y_true, y_pred, average='weighted')
0.26...
>>> f1_score(y_true, y_pred, average=None)
array([0.8, 0. , 0. ])
>>> y_true = [0, 0, 0, 0, 0, 0]
>>> y_pred = [0, 0, 0, 0, 0, 0]
>>> f1_score(y_true, y_pred, zero_division=1)
1.0...

SET FOREIGN_KEY_CHECKS=0;

   >>> x = 20 # x is a variable
  
  >>> if x < 50: # if condition
  ...    print('(first suite)')
  ...    print('x is small')
  ... else: else condition
  ...    print('(second suite)')
  ...    print('x is large')
  ...
 (first suite)
 x is small
                                
                                

keys, values)) # {'a': 2, 'c': 4, 'b': 3}
 
 
#make a function: def is the keyword for the function:
def to_dictionary(keys, values):
 
 
#return is the keyword that tells program that function has to return value   
return dict(zip(keys, values))
 
  
 
# keys and values are the lists:
 
keys = ["a", "b", "c"]   
 
values = [2, 3, 4]
                                
                                

People = 30
Cars = 40
Trucks = 14
# line 1,2,3 assign the value to variables
If cars > people: Using if statement
  Print(“we should take the  cars.”)
Elif cars < people: if 1st is false execute elif
  print(“we should not take the car.”)
else : # if both are false then execute else:
    print(“we can’t decide.”)
                               
                                

People = 20
Cats = 30
Dogs = 15
# line 1,2 and 3 assigning values to variables 
If people < cats: #1st condition
print(“too many cats”)
If people > cats: #2nd condition
print(“not many cats.”) # 3rd condition
If people > dogs:
print(“ the world is dry.”)
                              
                                

x = int(input("Please enter an integer: "))
Please enter an integer: 42 #getting input from user
>>> if x < 0: #1st condition
...    x = 0
...    print('Negative changed to zero')
... elif x == 0: #2nd condition
...    print('Zero')
... elif x == 1: #3rd condition
...    print('Single')
... else: #4th condition
...    print('More')                               
                                

# a characters list
          1.characters = ['a', 'b', 'c', 'd', 'e', 'f']
          2.characters.clear()
                                
                                

# animals list
1.animals = ['cat', 'dog', 'rabbit']

# list of wild animals
2.wild_animals = ['tiger', 'fox']

# appending wild_animals list to the animals list
3.animals.append(wild_animals)

4.print('Updated animals list: ', animals)                                
                                

 Lucky_numbers = [“3”, “7”, “15”, “32”, “42”]                               
                                

 #declare two set the range
1.i = 1
2.j = 5
#use while loop for i
3.while i < 4:
#use while loop for j    
4.while j < 8:
        5.print(i, ",", j)
        6.j = j + 1
        7.i = i + 1
Output:
1 , 5
2 , 6
3 , 7                               
                                

1.# For-Else Syntax

2.for item in seq:
    3.statement 1
    4.statement 2
    5.if <cond>:
        6.break
7.Else:
8.Example:
     9.birds = ['Belle', 'Coco', 'Juniper', 'Lilly', 'Snow']
10.ignoreElse = False


11.for theBird in birds:
    12.print(theBird )
    13.if ignoreElse and theBird is 'Snow':
        14.break
15.else:
    16.print("No birds left.")
                              
                                

days = 0
week = [‘Monday’, ‘Tuesday’, ‘Wednesday’, ‘Thursday’, ‘Friday’, ‘Saturday’, 3.‘Sunday’]
while day < 7:
print(“Today is” + week[days])
days += 1
                                
                                

def minus_key(key, dictionary):

shallow_copy = dict(dictionary)

del shallow_copy[key]

return shallow_copy
                               
                                

>>> stuff = {‘name’ : ‘Zed’, ‘age’ : 39, ‘height’ : 6 * 12 +1}
>>. print(stuff [‘name’])
Zed
>>> print(stuff [‘age’])
39
>>> print(stuff [‘height’])
74
>>> stuff [‘city’] = “SF”
>>. print(stuff[‘city’])
SF
                                
                                

n = 2

s ="Programming"

print(s * n) # ProgrammingProgramming

def byte_size(string):

  return(len(string.encode('utf-8')))

byte_size('😀’) # 4
byte_size('Hello World') # 11

Use functools.reduce() to perform right-to-left function composition. The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.
from functools import reduce

1.def compose(*fns):
  2.return reduce(lambda f, g: lambda *args: f(g(*args)), fns)
EXAMPLES
add5 = lambda x: x + 5
multiply = lambda x, y: x * y
multiply_and_add_5 = compose(add5, multiply)

multiply_and_add_5(5, 2) # 15

#define a function 
 Def cube(num)
      #write the formula of cube
      return num*num*num
     #give the number to calculate the cube 
     cube(3)
   # print the cube of that number simply by using print command
    print(cube(3))
     “return” keyword means that function have to return          value

 # give a name of function after def
 1.def sayhi():
      #put the statement in the function  
     2.print(“hello world”)
#call function by name:
3.sayhi()


Output: 
Hello world

# Program to add natural
# numbers upto 
# sum = 1+2+3+...+n

# To take input from the user,
# n = int(input("Enter n: "))

1.n = 10

# initialize sum and counter
2.sum = 0
3.i = 1

4.while i <= n:
   5. sum = sum + i
   6. i = i+1    # update counter

# print the sum
7.print("The sum is", sum)

When you run this code output will be:
Enter n: 10
The sum is 55

#define function
defall_unique(lst):

   return len(lst) == len(set(lst))
   
x = [1,1,2,2,3,2,3,4,5,6]


y = [1,2,3,4,5]


all_unique(x) # False
all_unique(y) # True

This method gets vowels (‘a’, ‘e’, ‘i’, ‘o’, ‘u’) found in a string.
   
#make a function:
def get_vowels(string):

#return is the keyword which means function have to return value: 
 return [each for each in string if each in 'aeiou']


#assign the words and function will return vowels words.
get_vowels('foobar') # ['o', 'o', 'a']


get_vowels('gym') # []

#use print command
1.print (“Mary had a little lamb.”)
2.print (“I am 19 years old.”)

def byte_size(string):




 return(len(string.encode('utf-8')))


  


 


byte_size('😀’) # 4
byte_size('Hello World') # 11

#define a function 
 1.Def cube(num)
      #write the formula of cube
      2.return num*num*num
     #give the number to calculate the cube 
     3.cube(3)
   # print the cube of that number simply by using print command
    4.print(cube(3))
     5.“return” keyword means that function have to return value         

 
def merge_two_dicts(a, b):
 
 
   c = a.copy()   # make a copy of a
 
   c.update(b)    # modify keys and values of a with the ones from b
 
   return c
 
 
 
 
 
a = { 'x': 1, 'y': 2}
 
b = { 'y': 3, 'z': 4}
 
 
print(merge_two_dicts(a, b)) # {'y': 3, 'x': 1, 'z': 4}
 
 

#make two lists:
1.num_list = [1, 2, 3]
2.alpha_list = ['a', 'b', 'c']

#use for loop for 1st list:
3.for number in num_list:
#print the list    
4.print(number)
#use for loop for @nd list:    
5.for letter in alpha_list:

# animals list
1.animals = ['cat', 'dog', 'rabbit', 'guinea pig']

# 'rabbit' is removed
2.animals.remove('rabbit')

# Updated animals List
3.print('Updated animals list: ', animals)

“Extend”  Allow to take a list and append another list at the end of it.
# language list
1.language = ['French', 'English', 'German']

# another list of language
2.language1 = ['Spanish', 'Portuguese']

3.language.extend(language1)

# Extended List
4.print('Language List: ', language)

When you run the program, the output will be:
Language List:  ['French', 'English', 'German', 'Spanish', 'Portuguese']

 1. var = 100 # var is a variable.
2.if var < 200:
   3.print "Expression value is less than 200"
   4.if var == 150:
      5.print "Which is 150"
   6.elif var == 100:
      7.print "Which is 100"
   8.elif var == 50:
      9.print "Which is 50"
   10.elif var < 50:
      11.print "Expression value is less than 50"
12.else:
   13.print "Could not find true expression"
 
14.print "Good bye!"
 
When the above code is executed, it produces following result −
Expression value is less than 200
Which is 100
Good bye!

#In computer programming, an iterator is an object that enables a programmer to traverse a container, particularly lists.
# define function:
1.def unfold(fn, seed):
  2.def fn_generator(val):
    3.while True: 
      4.val = fn(val[1])
     5.-5 if val == False: break
      6.yield val[0]
  7.return [i for i in fn_generator([None, seed])]
EXAMPLES
f = lambda n: False if n > 50 else [-n, n + 10]
unfold(f, 10) # [-10, -20, -30, -40,

month_conversion = {
“Jan” = “January”
“Feb” = “February”
“Mar” = “March”
“Apr” = “April”
“Jun” = “June”
}
# keys must be unique:
print(month_conversion[“Mar”])


Output”
           March

1.People = 30
2.Cars = 40
3. Trucks = 14
     # line 1,2,3 assign the value to variables
4.If cars > people: #Using if statement
   5.Print(“we should take the  cars.”)
6.Elif cars < people: #if 1st is false execute elif
     7.print(“we should not take the car.”)
8.else : # if both are false then execute else:
          9.print(“we can’t decide.”)

#assign a value to a variable:
types_of_people = 10 
# make a string using variable name:
X = f “there are {types_of_people} types of people.”

Output:
There are 10 types of people

  #use for loop and set the range
for index in range(10):
  Print (index)
           
           #when you run this program, the output will be:
               0 
               1 
               2 
               3 
               4 
               5
               6
               7
               8 
               9
                  

def max_by(lst, fn):
  return max(map(fn, lst))

from summarizer import Summarizer

body = '''
your text body
'''

model = Summarizer()
result = model(body, min_length=120)
full = ''.join(result)
print(full)

pip install youtube-dl
youtube-dl --yes-playlist --write-auto-sub https://www.youtube.com/playlist?list=PLJ8cMiYb3G5czofUrrizDiyC_yNLOe_CF

listing = os.listdir(path) 
num_samples=size(listing)
print num_samples

for file in listing:
    im = Image.open(path1 + '/' + file)   
    img = im.resize((img_rows,img_cols))
    gray = img.convert('L')
    gray.save(path2 +'/' +  file, "PNG")

>>> int(3.7)
3

>>> int(-3.4)
-3

>>> int(round(3.8))
4

from datetime import datetime

datetime_object = datetime.strptime('Jun 1 2005  1:33PM', '%b %d %Y %I:%M%p')

def when(predicate, when_true):
  return lambda x: when_true(x) if predicate(x) else x
  
EXAMPLES
double_even_numbers = when(lambda x: x % 2 == 0, lambda x : x * 2)
double_even_numbers(2) # 4
double_even_numbers(1) # 1

def unfold(fn, seed):
  def fn_generator(val):
    while True: 
      val = fn(val[1])
      if val == False: break
      yield val[0]
  return [i for i in fn_generator([None, seed])]
  
  
EXAMPLES
f = lambda n: False if n > 50 else [-n, n + 10]
unfold(f, 10) # [-10, -20, -30, -40, -50]

from functools import reduce

def compose(*fns):
  return reduce(lambda f, g: lambda *args: f(g(*args)), fns)


EXAMPLES
add5 = lambda x: x + 5
multiply = lambda x, y: x * y
multiply_and_add_5 = compose(add5, multiply)

multiply_and_add_5(5, 2) # 15

import numpy as np

def pagerank(M, num_iterations=100, d=0.85):
    N = M.shape[1]
    v = np.random.rand(N, 1)
    v = v / np.linalg.norm(v, 1)
    iteration = 0
    while iteration < num_iterations:
        iteration += 1
        v = d * np.matmul(M, v) + (1 - d) / N
    return v

from html.parser import HTMLParser

class MyHTMLParser(HTMLParser):
    def handle_starttag(self, tag, attrs):
        print("Encountered a start tag:", tag)
    def handle_endtag(self, tag):
        print("Encountered an end tag :", tag)
    def handle_data(self, data):
        print("Encountered some data  :", data)

parser = MyHTMLParser()
parser.feed('<html><head><title>Test</title></head>'
            '<body><h1>Parse me!</h1></body></html>')
           

def hanoi(n, source, helper, target):
    if n > 0:
        # move tower of size n - 1 to helper:
        hanoi(n - 1, source, target, helper)
        # move disk from source peg to target peg
        if source:
            target.append(source.pop())
        # move tower of size n-1 from helper to target
        hanoi(n - 1, helper, source, target)
        
source = [4,3,2,1]
target = []
helper = []
hanoi(len(source),source,helper,target)

print source, helper, target
    
Result:
    Move disk 1 from A to B
    Move disk 2 from A to C
    Move disk 1 from B to C
    Move disk 3 from A to B
    Move disk 1 from C to A
    Move disk 2 from C to B
    Move disk 1 from A to B

import re
import random
import os

# GLOBAL VARIABLES
grid_size = 81

def isFull (grid):
    return grid.count('.') == 0
  
# can be used more purposefully
def getTrialCelli(grid):
  for i in range(grid_size):
    if grid[i] == '.':
      print 'trial cell', i
      return i
      
def isLegal(trialVal, trialCelli, grid):

  cols = 0
  for eachSq in range(9):
    trialSq = [ x+cols for x in range(3) ] + [ x+9+cols for x in range(3) ] + [ x+18+cols for x in range(3) ]
    cols +=3
    if cols in [9, 36]:
      cols +=18
    if trialCelli in trialSq:
      for i in trialSq:
        if grid[i] != '.':
          if trialVal == int(grid[i]):
            print 'SQU',
            return False
  
  for eachRow in range(9):
    trialRow = [ x+(9*eachRow) for x in range (9) ]
    if trialCelli in trialRow:
      for i in trialRow:
        if grid[i] != '.':
          if trialVal == int(grid[i]):
            print 'ROW',
            return False
  
  for eachCol in range(9):
    trialCol = [ (9*x)+eachCol for x in range (9) ]
    if trialCelli in trialCol:
      for i in trialCol:
        if grid[i] != '.':
          if trialVal == int(grid[i]):
            print 'COL',
            return False
  print 'is legal', 'cell',trialCelli, 'set to ', trialVal
  return True

def setCell(trialVal, trialCelli, grid):
  grid[trialCelli] = trialVal
  return grid

def clearCell( trialCelli, grid ):
  grid[trialCelli] = '.'
  print 'clear cell', trialCelli
  return grid


def hasSolution (grid):
  if isFull(grid):
    print '\nSOLVED'
    return True
  else:
    trialCelli = getTrialCelli(grid)
    trialVal = 1
    solution_found = False
    while ( solution_found != True) and (trialVal < 10):
      print 'trial valu',trialVal,
      if isLegal(trialVal, trialCelli, grid):
        grid = setCell(trialVal, trialCelli, grid)
        if hasSolution (grid) == True:
          solution_found = True
          return True
        else:
          clearCell( trialCelli, grid )
      print '++'
      trialVal += 1
  return solution_found

def main ():
  #sampleGrid = ['2', '1', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '3', '1', '.', '.', '.', '.', '9', '4', '.', '.', '.', '.', '7', '8', '2', '5', '.', '.', '4', '.', '.', '.', '.', '.', '.', '6', '.', '.', '.', '.', '.', '1', '.', '.', '.', '.', '8', '2', '.', '.', '.', '7', '.', '.', '9', '.', '.', '.', '.', '.', '.', '.', '.', '3', '1', '.', '4', '.', '.', '.', '.', '.', '.', '.', '3', '8', '.']
  #sampleGrid = ['.', '.', '3', '.', '2', '.', '6', '.', '.', '9', '.', '.', '3', '.', '5', '.', '.', '1', '.', '.', '1', '8', '.', '6', '4', '.', '.', '.', '.', '8', '1', '.', '2', '9', '.', '.', '7', '.', '.', '.', '.', '.', '.', '.', '8', '.', '.', '6', '7', '.', '8', '2', '.', '.', '.', '.', '2', '6', '.', '9', '5', '.', '.', '8', '.', '.', '2', '.', '3', '.', '.', '9', '.', '.', '5', '.', '1', '.', '3', '.', '.']
  sampleGrid = ['.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '4', '6', '2', '9', '5', '1', '8', '1', '9', '6', '3', '5', '8', '2', '7', '4', '4', '7', '3', '8', '9', '2', '6', '5', '1', '6', '8', '.', '.', '3', '1', '.', '4', '.', '.', '.', '.', '.', '.', '.', '3', '8', '.']
  printGrid(sampleGrid, 0)
  if hasSolution (sampleGrid):
    printGrid(sampleGrid, 0)
  else: print 'NO SOLUTION'

  
if __name__ == "__main__":
    main()

def printGrid (grid, add_zeros):
  i = 0
  for val in grid:
    if add_zeros == 1:
      if int(val) < 10: 
        print '0'+str(val),
      else:
        print val,
    else:
        print val,
    i +=1
    if i in [ (x*9)+3 for x in range(81)] +[ (x*9)+6 for x in range(81)] +[ (x*9)+9 for x in range(81)] :
        print '|',
    if add_zeros == 1:
      if i in [ 27, 54, 81]:
        print '\n---------+----------+----------+'
      elif i in [ (x*9) for x in range(81)]:
        print '\n'
    else:
      if i in [ 27, 54, 81]:
        print '\n------+-------+-------+'
      elif i in [ (x*9) for x in range(81)]:
        print '\n'

import re
from collections import Counter

def words(text): return re.findall(r'\w+', text.lower())

WORDS = Counter(words(open('big.txt').read()))

def P(word, N=sum(WORDS.values())): 
    "Probability of `word`."
    return WORDS[word] / N

def correction(word): 
    "Most probable spelling correction for word."
    return max(candidates(word), key=P)

def candidates(word): 
    "Generate possible spelling corrections for word."
    return (known([word]) or known(edits1(word)) or known(edits2(word)) or [word])

def known(words): 
    "The subset of `words` that appear in the dictionary of WORDS."
    return set(w for w in words if w in WORDS)

def edits1(word):
    "All edits that are one edit away from `word`."
    letters    = 'abcdefghijklmnopqrstuvwxyz'
    splits     = [(word[:i], word[i:])    for i in range(len(word) + 1)]
    deletes    = [L + R[1:]               for L, R in splits if R]
    transposes = [L + R[1] + R[0] + R[2:] for L, R in splits if len(R)>1]
    replaces   = [L + c + R[1:]           for L, R in splits if R for c in letters]
    inserts    = [L + c + R               for L, R in splits for c in letters]
    return set(deletes + transposes + replaces + inserts)

def edits2(word): 
    "All edits that are two edits away from `word`."
    return (e2 for e1 in edits1(word) for e2 in edits1(e1))

class Solution(object):
    def letterCombinations(self, digits):
        """
        :type digits: str
        :rtype: List[str]
        """
        

# Python3 implementation of the approach 

# Function to sort the array such that 
# negative values do not get affected 
def sortArray(a, n): 

	# Store all non-negative values 
	ans=[] 
	for i in range(n): 
		if (a[i] >= 0): 
			ans.append(a[i]) 

	# Sort non-negative values 
	ans = sorted(ans) 

	j = 0
	for i in range(n): 

		# If current element is non-negative then 
		# update it such that all the 
		# non-negative values are sorted 
		if (a[i] >= 0): 
			a[i] = ans[j] 
			j += 1

	# Print the sorted array 
	for i in range(n): 
		print(a[i],end = " ") 


# Driver code 

arr = [2, -6, -3, 8, 4, 1] 

n = len(arr) 

sortArray(arr, n) 

>>> ["foo", "bar", "baz"].index("bar")
1

a = []

if not a:
  print("List is empty")

>>> from time import gmtime, strftime
>>> strftime("%Y-%m-%d %H:%M:%S", gmtime())
'2009-01-05 22:14:39'

import pathlib
pathlib.Path('/my/directory').mkdir(parents=True, exist_ok=True) 

import glob
print(glob.glob("/home/adam/*.txt"))

for idx, val in enumerate(ints):
    print(idx, val)

if 'key1' in dict:
  print "blah"
else:
  print "boo"

import time
time.sleep(5)   # Delays for 5 seconds. You can also use a float value.

x = tf.random_normal([300], mean = 5, stddev = 1)
y = tf.random_normal([300], mean = 5, stddev = 1)
avg = tf.reduce_mean(x - y)
cond = tf.less(avg, 0)
left_op = tf.reduce_mean(tf.square(x-y))
right_op = tf.reduce_mean(tf.abs(x-y))
out = tf.where(cond, left_op, right_op) #tf.select() has been fucking deprecated

newlist = old_list.copy()

>>> a = "545.2222"
>>> float(a)
545.22220000000004
>>> int(float(a))
545

if "blah" not in somestring: 
    continue