Dyanmically Naming Files

[buran]

all of the examples I have provided would do. Obviously the os.path functions will require less change in your code.

something that works with string formatting inside the .format(filename)

you can construct the new file name in the open function using os.path functions, but for sake of readability it's better to do it on separate line, e.g. replace line 26

for line in open(('{}_clean.csv').format(filename),'r'):

with

new_name = ''.join((os.path.splitext(filename)[0], '_clean.csv'))
for line in open(new_name, 'r'):