Problem with creating DataFrame using Dictionary

[ift38375]

I already shared code and error comes with line "ks.2016.count()" bcoz it not takes value 2016 as column.

Pandas allows to get access to columns of a dataframe instance as its attributes, e.g. df.column_name, but you need to be careful when using this approach. It is better to use .loc selector instead, e.g. df.loc[:, 2016].count().

when i am doing same thing with given dataframe then no error comes with alphabetical column name:

import pandas as pd
diSales= { 'Mon':{'qtr1':34500,'qtr2':56000,'qtr3':47000,'qtr4':49000},
           'Tues':{'qtr1':44900,'qtr2':46100,'qtr3':57000,'qtr4':59000},
           'Wed':{'qtr1':54500,'qtr2':51000,'qtr3':57000,'qtr4':58500},
           'Thrus':{'qtr1':61000}
         }
df = pd.DataFrame(diSales)
ks = df.Mon.count()
print(ks)

It gives output '4'

But when i am changing column names and taking numeric form column name as 2016,2017,2018,2019 so on. then it gives error of " Invalid syntax" when i am doing
ks = df.2016.count() .
Why ?