Counting Mulitple Values in a Python pandas Dataframe Column

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

df['SettlementDate'] = pd.TimedeltaIndex(df['SettlementDate'], unit='d') + dt.datetime(1900,1,1)

# function to replace rows in the provided column of the provided dataframe
# that match the provided string above the provided ratio with the provided string
def replace_matches_in_column(df, column, string_to_match, min_ratio = 47):
    # get a list of unique strings
    strings = df[column].unique()
    
    # get the top 10 closest matches to our input string
    matches = fuzzywuzzy.process.extract(string_to_match, strings, 
                                         limit=10, scorer=fuzzywuzzy.fuzz.token_sort_ratio)

    # only get matches with a ratio > 90
    close_matches = [matches[0] for matches in matches if matches[1] >= min_ratio]

    # get the rows of all the close matches in our dataframe
    rows_with_matches = df[column].isin(close_matches)

    # replace all rows with close matches with the input matches 
    df.loc[rows_with_matches, column] = string_to_match
    
    # let us know the function's done
    print("All done!")

# Setup fake key in both DataFrames to join on it

df1['key'] = 0
df2['key'] = 0

df1.merge(df2, on='key', how='outer')

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

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

df.drop_duplicates()

'${:,.2f}'.format(dfCombined['Amount'].sum())

(df.groupby('name')['ext price']
 .agg(['mean', 'sum'])
 .style.format('${0:,.2f}'))

# importing pandas as pd 
import pandas as pd 
  
# Creating the dataframe  
df = pd.read_csv("nba.csv") 
  
# Using regular expression to extract all 
# columns which has letter 'a' or 'A' in its name. 
df.filter(regex ='[aA]') 

# applying filter function 
df.filter(["Name", "College", "Salary"]) 

c3 = pd.Series(['China', 'US'])
df[df['countries'].isin(c1)]

# importing libraries 
from sklearn.ensemble import VotingClassifier ,BaggingClassifier, ExtraTreesClassifier, RandomForestClassifier
from sklearn.ensemble import AdaBoostClassifier,GradientBoostingClassifier
from sklearn.metrics import accuracy_score 
from numpy import mean,std
from sklearn.datasets import make_classification
from sklearn.model_selection import cross_val_score,RepeatedStratifiedKFold,train_test_split
from sklearn.linear_model import LogisticRegression,RidgeClassifier
from sklearn.neighbors import KNeighborsClassifier
from sklearn.tree import DecisionTreeClassifier
from sklearn.svm import SVC
from sklearn.naive_bayes import GaussianNB
from matplotlib import pyplot
from sklearn.datasets import load_wine,load_iris
from matplotlib.pyplot import figure
figure(num=2, figsize=(16, 12), dpi=80, facecolor='w', edgecolor='k')
import xgboost as xgb
from sklearn.feature_selection import SelectKBest,f_regression
from sklearn.linear_model import LinearRegression,BayesianRidge,ElasticNet,Lasso,SGDRegressor,Ridge
from sklearn.kernel_ridge import KernelRidge
from sklearn.preprocessing import LabelEncoder,OneHotEncoder,RobustScaler,StandardScaler
from sklearn.pipeline import make_pipeline,Pipeline
from sklearn.metrics import mean_squared_error
from sklearn.decomposition import PCA,KernelPCA
from sklearn.ensemble import ExtraTreesRegressor,GradientBoostingRegressor,RandomForestRegressor,VotingClassifier
from sklearn.model_selection import cross_val_score,KFold,GridSearchCV,RandomizedSearchCV,StratifiedKFold,train_test_split
from sklearn.base import BaseEstimator,clone,TransformerMixin,RegressorMixin
from sklearn.svm import LinearSVR,SVR
#import xgboost 
from xgboost import XGBRegressor
#Import Pandas
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import matplotlib
import seaborn as sns
import warnings
warnings.filterwarnings('ignore')
from scipy.stats import skew
from scipy.stats.stats import pearsonr
%matplotlib inline
seed = 1075
np.random.seed(seed)

.apply(lambda x: x.replace(',',',').replace(',',',').split(',')

for p in ax.patches:
    values = '{:.0f}'.format(p.get_height())
    x = p.get_x() + p.get_width()/2
    y = p.get_height()
    ax.annotate(values, (x, y),ha='center', va ='bottom', fontsize = 10)