Python '==' incorrectly returning false -

i'm trying difference of 2 files line line, , python returning false; when diff of same files, python (almost) returns false. goofy example, replicates problem on python 3.4.3.

file1.txt (example) 1 2 3  file1 = r"pathtofile\file1.txt" file2 = r"pathtofile\file1.txt" f1 = open(file1, "r") f2 = open(file2, "r")  line1 in f1:     found = false     line2 in f2:         if repr(line1) == repr(line2):             found = true             print("true")     if found == false:         print("false") 

python correctly identifies first line same, after false. can else replicate this? ideas?

you have exhausted iterator after first iteration on f2, need file.seek(0) go start of file.

for line1 in f1:     found = false     line2 in f2:         if repr(line1) == repr(line2):             print("true")     f2.seek(0) # reset pointer start of file 

you check first line of f1 against lines of f2, after first loop there nothing iterate over.

depending on want happen, either need break when find line matches or else reset found = false in inner loop.

if want matching lines store output in list or if files not big can use sets find find common lines.

with open("f1") f1, open("f2") f2:        st = set(f1)     common = st.intersection(f2) 

if want difference use st.difference(f2), lines in either both not in both use st.symmetric_difference(f2). depends on want do.

you might want check out filecmp , difflib