Python line remover

Question

Hi I have a large file that I want to delete the lines that contain the text ALL and print the file without spaces with just the remaining lines. I started a program

sourcefile = open('C:\\scoresfinal.txt', 'r')
filename2 = open('C:\\nohet.txt', 'w')

offending = ["HET"]

def fixup( filename ): 
    fin = open( filename ) 
    fout = open( filename2 , "w") 
    for line in fin.readlines(): 
        if True in [item in line for item in offending]:
            continue
        fout.write(line)
    fin.close() 
    fout.close() 

fixup(sourcefile)

but it doesn't work. any help?

here is my error:

Traceback (most recent call last):
  File "C:/Python Make Small File/hetcut2.py", line 18, in <module>
    fixup(sourcefile)
  File "C:/Python Make Small File/hetcut2.py", line 9, in fixup
    fin = open( filename )
    TypeError: coercing to Unicode: need string or buffer, file found

Answer 1

2) sourcefile and filename2 are files, not a string.

Answer 2

sourcefile = open('C:\\scoresfinal.txt', 'r')

defines sourcefile as a file object. So

fixup(sourcefile)

assigns sourcefile to be the value of the local variable filename in the fixup function.

Calling open(filename) thus tries to open an already-open file object, when open expected a string naming a file or filepath.

You could fix the code this way:

sourcefile = 'C:\\scoresfinal.txt'
filename2 = 'C:\\nohet.txt'

offending = ["HET"]

def fixup( filename ): 
    with open( filename ) as fin:
        with open( filename2 , "w") as fout:
            for line in fin: 
                if any(item in line for item in offending):
                    continue
                fout.write(line)
fixup(sourcefile)

The with open(...) as f statement is available in Python2.6 or better. In Python2.5 you can use the with statement if you put

from __future__ import with_statement

The advantage of doing it this way is that you are guaranteed to close the file handles with Python exits the with-block. (Notice the explicit calls to fin.close() and fout.close() were removed.)

Using with is not necessary to solve your immediate problem, but it is the future standard idiom in Python, so you might as well get used to it.

Answer 3

In the beginning, you open a file and store the handle inside of filename2. Then within the function, you are trying to use that filename2 as a – well – filename, when it is instead a handle to an already opened file.

If you want that to work, you have to set filename2 to the actual filename:

filename2 = 'C:\\nohet.txt'

Also, you should consider moving the target pathname into the function parameters, so it doesn't depend on some global variable.

Oh, and the same applies to sourcefile which is a file handle as well but which your function tries to use as a filename as well.

edit:

Like this:

def fixup( source, target, badWords ):
    fin = open( source ) 
    fout = open( target , "w" )

    for line in fin:
        if any( ( word in line ) for word in badWords ):
            continue
        fout.write( line )

    fin.close() 
    fout.close() 

offending = ["HET"]
fixup( 'C:\\scoresfinal.txt', 'C:\\nohet.txt', offending )

Answer 4

The question has already been answered (you are "opening the files twice") but I thought I should point out that you could tidy the code somewhat:

def fixup( filename ): 
    with fin as open(filename), fout as open(filename2 , "w") 
        for line in fin:
            if not any(word in line for word in offending):
                fout.write(line)

Also, you should consider using better variable names. fixup, filename, filename2 (ugh!) are not very illuminating.