i have tried the below code and getting results s i mentioned below.
code:
yday_mnth = '201905'
b = yday_mnth
x = 'yday_mnth'
print b
print x
Output here is as below:
201905
yday_mnth
Which means for b am getting value as 201905 however for x I'am getting yday_mnth 
as its a string 
however is there any way to convert the x to print value 
of yday_mnth? i.e 201905
 
    