Add spaces to the end of the field - python

Question

Hello, everybody.

I have a *.txt file in which there is a column with the product code and another column with the quantity value as below:

Cód.          qtd
7513020087041;5.0

879705341017;24.0

11713777;8.0

17565097;2.0

181420;20.0

181421;20.0

But the system to which I export this file does not accept because the code field must be formatted with 13 characters, and if it does not have the 13 characters it must be filled with white spaces as in the example below:

7513200870410;5.0

879075341017_;24.0

11713777_____;8.0

17565097_____;2.0

181420_______;20.0

181421_______;20.0

Note: Read '_' = ' spaces.

Answer 1

You can use ljust:

print('7513200870410'.ljust(13)) # '7513200870410'
print('181420'.ljust(13)) # '181420       '

Or format (python3.x):

print('{:<13}'.format(7513200870410)) # '7513200870410'
print('{:<13}'.format(181420)) # '181420       '

Example with your data for later saving to a file:

dados = '''
    7513020087041;5.0
    879705341017;24.0
    11713777;8.0
    17565097;2.0
    181420;20.0
    181421;20.0
'''

dados_new = ''
for d in dados.split():
    cod, qtd = d.split(';')
    dados_new += '{:<13};{}\n'.format(cod, qtd)

# guardar dados_new em um novo ficheiro:
""" OUTPUT
7513020087041;5.0
879705341017 ;24.0
11713777     ;8.0
17565097     ;2.0
181420       ;20.0
181421       ;20.0
"""

DEMONSTRATION

If you want to save to a file again with all formatted you can, after the code of the example above:

...
print('\n'.join('{};{}'.format(x,y) for x,y in dados_new), file=open('new_file.txt', 'w'))

# output:
"""
7513020087041;5.0
879705341017 ;24.0
11713777     ;8.0
17565097     ;2.0
181420       ;20.0
181421       ;20.0
"""

DEMONSTRATION