For循环将每一行打印到文件。 错误

Question

I'm trying to make a for loop that prints every line in a list to a file, however I get this error. Any help? Thanks

def write_file(filename, rabbitlist, foxlist, finallist, averagefox, averagerabbit):

    # Opens File for Data Input
    outfile = open(str(filename) + ".csv", 'w')

    # Writes Data to Newly Created File
    finalresult = "\n".join(", ".join(map(str, l)) for l in finallist)
    outfile.write(str("Day, Foxes, Rabbits, , Average Foxes, Average Rabbits\n"))
    lastline = [0, foxlist[0], rabbitlist[0], " ", averagefox, averagerabbit]
    for item in lastline:
        outfile.write(" %s", item)
    outfile.close()

The error I get is: Python: TypeError: takes exactly 1 argument (2 given)

Answer 1

.write only accepts 1 parameter so i think you can do this

def write_file(filename, rabbitlist, foxlist, finallist, averagefox, averagerabbit):

    # Opens File for Data Input
    outfile = open(str(filename) + ".csv", 'w')

    # Writes Data to Newly Created File
    finalresult = "\n".join(", ".join(map(str, l)) for l in finallist)
    outfile.write(str("Day, Foxes, Rabbits, , Average Foxes, Average Rabbits\n"))
    lastline = [0, foxlist[0], rabbitlist[0], " ", averagefox, averagerabbit]
    for item in lastline:
        outfile.write(" %s" % item)
    outfile.close()

Answer 2

Since you are wirting a csv, why not use the csv module. Your method then becomes:

import csv

def write_file(filename,
               rabbitlist,
               foxlist,
               finallist,
               averagefox,
               averagerabbit):
    header_row = ['Day','Foxes','Rabbits',' ','Average Foxes','Average Rabbits']
    with open(filename,'w') as f:
        writer = csv.writer(f, delimiter=',')
        writer.writerow(header_row)
        writer.writerows(finallist)
        writer.writerow([0,
                         foxlist[0],
                         rabbitlist[0],
                         " ",
                         averagefox,
                         averagerabbit])

The with_statement will automatically close the file, and the csv module has writerows which does what it the name suggests.

Answer 3

In python write method of File takes only one argument whereas you are passing two.

Either you can do outfile.write(" %s" %item)

Or better way is to use Pickle