open a file and changing its data

[thatos]

I have developed a code to encrypt so what I would like to know is how can I open a file contaning certain data and change the data to encypted message for axample suppose my file in named see.txt and what I wrote inside is 'hello there' and after i encrypt in to maybe 'wwjkahkjahsjka' and I want my file see.txt to contain that encypted text not that 'hello there' which I had before if you are intersted to know I'm using vigenere cipher

[William Manley]

Basically, here:

f = open('see.txt','r')
data = '\n'.join(f.readlines())
f.close()
# right here is where you would modify the data -- encrypting it however you want.
 
f = open('see.txt','w') # mode "w" will overwrite the file's contents.
f.write(data)
f.close()
 
#and you're done.
 

I think this is all right but I didn't have a chance to test it, not on a machine with python right now.