There are multiple ways in which you can use if else construct in the command line in python. For example, bash supports multiline statements, which you can use like:
$ python -c '
> a = True
> if a:
> print("a is true")
> 'This will give the output:
a is true
If you prefer to have the python statement in a single line, you can use the \n newline between the commands. For example,
$ python -c $'a = True\nif a: print("a is true");'This will give the output:
a is true