Salary.date = pd.to_datetime(Salary.date, format="%d-%m-%Y")
check_Salary_date = Salary[Salary['date'].dt.day <= 5].groupby('date').sum()
check_Salary_date.index = check_Salary_date.index.strftime('%d-%b-%y')
check_Salary_date.index.name = 'Date'
if not check_Salary_date.empty:
    print("Is salary credited before 5th:", True)
    print("List of salary credited before 5th : n", check_Salary_date)
else:
    print("Is salary credited before 5th:", False)
sum_Salary = Salary.groupby('date').sum()
sum_Salary = Salary.groupby(pd.Grouper(key='date', freq='1M')).sum()
sum_Salary_3months = Salary.groupby(pd.Grouper(key='date', freq='1M')).mean().dropna(subset=['Salary']).tail(3)
avg_Salary_3months = sum_Salary_3months['Salary'].mean()
sum_Salary.index = sum_Salary.index.strftime('%b-%y')
sum_Salary.index.name = 'Date'
total_Salary = len(sum_Salary.axes[0])
print("nSalary received per month n", sum_Salary)
print("--------------")
print("Avg Salary of last 3 months :", avg_Salary_3months)

Is salary credited before 5th: True
List of date where salary received before 5th :
           Balance before Salary   Salary
Date
03-Aug-18                 176.48  14783.0
04-Sep-18                  48.48  16249.0
05-Oct-18                 241.48  14448.0

Salary received per month
        Balance before Salary   Salary
Date
Jun-18                  27.20  15300.0
Jul-18                  88.20  15300.0
Aug-18                 176.48  14783.0
Sep-18                  48.48  16249.0
Oct-18                 241.48  14448.0
Nov-18                  49.48  15663.0
--------------
Avg Salary of last 3 months : 15453.333333333334
--------------

[{"Is salary credited before 5th": "yes"},

{
    "List of salary credited before 5th": {
        "Balance before Salary": {
          "03-Aug-18":176.48,
          "04-Sep-18":48.48,
          "05-Oct-18":241.48

        },
        "Salary": {
        "03-Aug-18":14783.0,
        "04-Sep-18":16249.0,
        "05-Oct-18":14448.0

        }
    }
},
{
    "Salary received per month": {
        "Balance before Salary": {
          "Jun-18":27.2,
          "Jul-18":88.2,
          "Aug-18":176.48,
          "Sep-18":48.48,
          "Oct-18":241.48,
          "Nov-18":49.48

        },
        "Salary": {
          "Jun-18":15300.0,
          "Jul-18":15300.0,
          "Aug-18":14783.0,
          "Sep-18":16249.0,
          "Oct-18":14448.0,
          "Nov-18":15663.0}
    }
},

{"Avg Salary of last 3 months" : 15453.333333333334}
]