How do I put a variable inside a string?

Question

I would like to put an int into a string. This is what I am doing at the moment:

num = 40
plot.savefig(\'hanning40.pdf\') #problem          


        

Answer 1

plot.savefig('hanning(%d).pdf' % num)

The % operator, when following a string, allows you to insert values into that string via format codes (the %d in this case). For more details, see the Python documentation:

https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting