I want to change the number format of a column in a dataframe. For ex, I want to change the number from 10.0 to 10

I have a data frame like:

s.no  appointment number
1     101.0
2     108.0
3     167.0
...

I want to change the appointment number column format to this way:

s.no  appointment number
1     101
2     108
3     167

I am a beginner in Python.