df['date_of_order'] = pd.to_datetime(df['date_of_order']) # if you haven't converted it already
df.groupby(df['date_of_order'].dt.to_period('Q'))['column to aggregate'].agg(...)
Preview:
downloadDownload PNG
downloadDownload JPEG
downloadDownload SVG
Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!
Click to optimize width for Twitter