Unbound Local Error in Python for File-reading

Question

I have a function that reads in a data file and returns the values in that file as a list printing comments.

def loadcsv(filename):
    """Loads a comma-separated-value file (.csv) and returns a list of all the   numerical values, ignoring comments and any malformatted data."""
    """Function should ignore bad data, but print all comments."""
    datafile = open(filename)
    global datafile
    numbers = []
    for line in datafile:
    if line[0] == "#":
        print line
    elif line[0] != "#" or type(line[0]) != type(0) or type(line[0]) != type(0):
        print "Bad Data"
    else:
        numbers.append(line)
    datafile.close()
    return numbers

Not sure how I get the error given my declaration of datafile as global.

Answer 1

The global statement needs to be the first line in your function, so just swap the global datafile and datafile = open(filename) lines.