Compare Two Files And Write To A New File But Only Output A Few Lines?

I want to compare two txt files with all lines,but when i run the code it response only a few results,the loop is not effective run，It seems missed a lot of lines in File1,only a

Solution 1:

You should re-open File2 in inner loop or use file.seek to jump to the start of the file because after the first iteration the file pointer is at the end of File2.

Help on file.seek:

>>> print file.seek.__doc__
seek(offset[, whence]) -> None.  Move tonew file position.

Argument offsetis a byte count.  Optional argument whence defaults to0 (offsetfromstartof file, offset should be >=0); other valuesare1
(move relative tocurrent position, positive or negative), and2 (move
relative toendof file, usually negative,....

Solution 2:

Thanks to the answers above.And with my special appreciation to Nisan.H and Ashwini Chaudhary，I've solved the problem by your help,add only a line before "for line2 in File2"~~~

def compareLines(filename1,filename2):

File1=open(filename1,'r')
File2=open(filename2,'r')
File3=open("Result.txt",'w')

finalList=[]

for line1 in File1:
    File2.seek(0)
    for line2 in File2:
        set1=set(line1.split(" "))
        set2=set(line2.split(" "))
        print line1
        print line2
        similarNumber=len(set1.intersection(set2))/float(len(set1.union(set2)))
        File3.write('Simmilar rate:'+str(similarNumber)+' '+str(len(set1.intersection(set2)))+" words in incoindence\n")
        finalList.append(similarNumber)

File1.close()
File2.close()
File3.close()

os.remove(filename1)
os.remove(filename2)

return finalList