Save the same content to .csv file as print command

问题

Print command showing me something like this (I have more as 3 rows, but this is only part of example):

O;4;Line[63];CPUA.DB1610.4122,X1;RW
V;5;Enable_maintenance_mode;;
V;5;Maintenance_start_motor;CPUA.DB1610.4124,X0;RW
O;4;Line[64];CPUA.DB1610.4124,X1;RW

I'm trying save the same content on csv file, but on csv I have only one row and this format. The question is, how to save to the csv file the save what print showing ?

O,;,4,;,L,i,n,e,[,6,4,],;,C,P,U,A,.,D,B,1,6,1,0,.,4,1,2,4,|,|,X,1,;,R,W

They are saving me only one row on csv file

This is my code:

for i in range((len(result)-1)):
 print(str(result[i][0]) + ';' + str(result[i][1]) + ';' + result[i][2] + ';' + str(adress[i]))
 with open(source_file[:-4] + '_test.csv', "w") as f:
  writer = csv.writer(f)
  writer.writerow(str(result[i][0]) + ';' + str(result[i][1]) + ';' + result[i][2] + ';' + str(adress[i]))

I don't know what I'm doing wrong. Can someone help me solve this problem ?

result contains:

['V', '5', 'Enable_maintenance_mode', "S7:[CPUA]DB1610', 'X4124.0", 'B', 'RW', '0', "0']"]
['V', '5', 'Maintenance_start_motor', "S7:[CPUA]DB1610', 'X4124.1", 'B', 'RW', '0', "0']"]
['O', '4', 'Line[64]', '', '', "']"]
['V', '5', 'Enable_maintenance_mode', "S7:[CPUA]DB1610', 'X4126.0", 'B', 'RW', '0', "0']"]

@Martin Evans Your example look really good. But I need only part of row from result and save as csv. Can I make somethink like this ?

csv_output = csv.writer(f_output, lineterminator='\n')
 for line in result:
 #csv_output.writerow(line)
 csv_output.writerow(str(result[line][0]) + ';' + str(result[line][1]) + ';' + result[line][2] + ';' + str(adress[line]))

But I have error: TypeError: list indices must be integers, not list

回答1:

The csv library is designed to take a list of column entries and convert it automatically into a whole csv row by adding the necessary delimiters for you. Your print statement is simulating this by appending the ; between each column entry. You can specify the delimiter to use when creating the csv.writer, in your example this is ;:

import csv

result = [
    ['V', '5', 'Enable_maintenance_mode', "S7:[CPUA]DB1610', 'X4124.0", 'B', 'RW', '0', "0']"],
    ['V', '5', 'Maintenance_start_motor', "S7:[CPUA]DB1610', 'X4124.1", 'B', 'RW', '0', "0']"],
    ['O', '4', 'Line[64]', '', '', "']"],
    ['V', '5', 'Enable_maintenance_mode', "S7:[CPUA]DB1610', 'X4126.0", 'B', 'RW', '0', "0']"]]

address = [
    "CPUA.DB1610.4122,X1;RW",
    "",
    "CPUA.DB1610.4124,X0;RW",
    "CPUA.DB1610.4124,X1;RW"]

with open('output.csv', 'w', newline='') as f_output:
    csv_output = csv.writer(f_output, delimiter=';')

    for r, a in zip(result, address):
        csv_output.writerow(r[0:3] + a.split(';'))

When using a csv.writer() in Python 3.x, you should always open the file with w and set newline=''. Also it is easier to iterate through your result entries directly without using range() and indexing. As you appear to have two equal length lists, you can use zip to give you an element from each as you iterate.

This would give you an output file as follows:

V;5;Enable_maintenance_mode;CPUA.DB1610.4122,X1;RW
V;5;Maintenance_start_motor;
O;4;Line[64];CPUA.DB1610.4124,X0;RW
V;5;Enable_maintenance_mode;CPUA.DB1610.4124,X1;RW

Note, you have not provided a sample for address so this is based on your example output.

来源：https://stackoverflow.com/questions/36834400/save-the-same-content-to-csv-file-as-print-command

标签

python

csv

save