用python编写输出文本文件

Question

Currently i have a list of list containing:

lst = [[1,2],[5,4],[10,9]]

and I'm trying to write the output in the form of a text file where it is formatted

1      2
5      4
10     9

I tried:

newfile = open("output_file.txt","w")
for i in range(len(lst)):
    newfile.write(i)
newfile.close()

but I'm getting the error:

TypeError: write() argument must be str, not list

would appreciate some help on this.

Answer 1

You should change your int values to str and add newline char end of it as below :

lst = [[1,2],[5,4],[10,9]]

newfile = open("output_file.txt","w")
for i in lst:
    newfile.write(str(i[0]) + ' ' + str(i[1]) + '\n')
newfile.close()

output file is :

1 2
5 4
10 9

Answer 2

You can use a format string instead:

lst = [[1,2],[5,4],[10,9]]
with open("output_file.txt","w") as newfile:
    for i in lst:
        newfile.write('{:<7}{}\n'.format(*i))

Answer 3

You are getting the error because you are directly printing the list elements, perhaps the write method of the file need the parameter to be the string and you're passing directly the list elements. Do a thing explicitly convert the items of the list to the string and print.

 newfile = open("output_file.txt","w")
 for i in range(len(lst)):
    newfile.write(str(i))
 newfile.close()

Answer 4

you can use numpy module to write into text file like below.

import numpy as np
lst = [[1,2],[5,4],[10,9]]
np.savetxt('output_file.txt',lst,fmt='%d')

Thanks

Answer 5

Write it with a formatted string

with open('output.txt', 'w') as f:
    for i in lst:
        f.write('{}\t{}\n'.format(i[0], i[1]))

 (xenial)vash@localhost:~/python/stack_overflow/sept$ cat output.txt 1 2 5 4 10 9