How to change the value of a line in specific column in a txt file Python?

I have a text file with 1 column of different values (floating and integer) and I would like to change a value according to its line. my code is as follows: but I did it knowing what value I should replace, how to do it according to the line?

with open('table1.txt', 'r+') as file:

    text = file.read()

    i = text.index('3.6') # 3.6 = old value

    file.seek(0)

    file.write(text[:i] + '7.84' + text[i + len('3.6'):]) # 7.84 = new value

Secondly, how can I choose a row when there are several columns in my file? For example, column 2 row 1? ? thanx

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

This is not a python question. Please move this question to unix.stackexchange.com or similar sites

– Kevin Fang
Nov 23 '18 at 3:06

so you are asking how to use sed or how to process your txt file with python?

– Enix
Nov 23 '18 at 3:06

Yes, I'm sorry, I was wrong, I just corrected now is my good question

– F.Moab
Nov 23 '18 at 3:27

you can use file.readline() or use iterator on file object to read line by line and use var count to count line no

– Ravindhar Konka
Nov 23 '18 at 4:52

add a comment |

with open('table1.txt', 'r+') as file:

    text = file.read()

    i = text.index('3.6') # 3.6 = old value

    file.seek(0)

    file.write(text[:i] + '7.84' + text[i + len('3.6'):]) # 7.84 = new value

Secondly, how can I choose a row when there are several columns in my file? For example, column 2 row 1? ? thanx

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

This is not a python question. Please move this question to unix.stackexchange.com or similar sites

– Kevin Fang
Nov 23 '18 at 3:06

so you are asking how to use sed or how to process your txt file with python?

– Enix
Nov 23 '18 at 3:06

Yes, I'm sorry, I was wrong, I just corrected now is my good question

– F.Moab
Nov 23 '18 at 3:27

you can use file.readline() or use iterator on file object to read line by line and use var count to count line no

– Ravindhar Konka
Nov 23 '18 at 4:52

add a comment |

with open('table1.txt', 'r+') as file:

    text = file.read()

    i = text.index('3.6') # 3.6 = old value

    file.seek(0)

    file.write(text[:i] + '7.84' + text[i + len('3.6'):]) # 7.84 = new value

Secondly, how can I choose a row when there are several columns in my file? For example, column 2 row 1? ? thanx

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

with open('table1.txt', 'r+') as file:

    text = file.read()

    i = text.index('3.6') # 3.6 = old value

    file.seek(0)

    file.write(text[:i] + '7.84' + text[i + len('3.6'):]) # 7.84 = new value

Secondly, how can I choose a row when there are several columns in my file? For example, column 2 row 1? ? thanx

python

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

edited Nov 23 '18 at 4:36

eyllanesc

77.1k103156

asked Nov 23 '18 at 2:58

F.Moab

asked Nov 23 '18 at 2:58

F.Moab

asked Nov 23 '18 at 2:58

F.Moab

This is not a python question. Please move this question to unix.stackexchange.com or similar sites

– Kevin Fang
Nov 23 '18 at 3:06

so you are asking how to use sed or how to process your txt file with python?

– Enix
Nov 23 '18 at 3:06

Yes, I'm sorry, I was wrong, I just corrected now is my good question

– F.Moab
Nov 23 '18 at 3:27

you can use file.readline() or use iterator on file object to read line by line and use var count to count line no

– Ravindhar Konka
Nov 23 '18 at 4:52

add a comment |

This is not a python question. Please move this question to unix.stackexchange.com or similar sites

– Kevin Fang
Nov 23 '18 at 3:06

so you are asking how to use sed or how to process your txt file with python?

– Enix
Nov 23 '18 at 3:06

Yes, I'm sorry, I was wrong, I just corrected now is my good question

– F.Moab
Nov 23 '18 at 3:27

you can use file.readline() or use iterator on file object to read line by line and use var count to count line no

– Ravindhar Konka
Nov 23 '18 at 4:52

This is not a python question. Please move this question to unix.stackexchange.com or similar sites

– Kevin Fang
Nov 23 '18 at 3:06

so you are asking how to use sed or how to process your txt file with python?

– Enix
Nov 23 '18 at 3:06

Yes, I'm sorry, I was wrong, I just corrected now is my good question

– F.Moab
Nov 23 '18 at 3:27

you can use file.readline() or use iterator on file object to read line by line and use var count to count line no

– Ravindhar Konka
Nov 23 '18 at 4:52

add a comment |

1 Answer
1

active

oldest

votes

if columns in your file are splited by space:

def change_value(column, row, new_value):

    lines = 

    with open('table1.txt', 'r+') as file:

        for line in file:

            lines.append(line.rstrip().split())



        lines[row - 1][column - 1] = str(new_value)

        file.seek(0)

        for line in lines:

            line[-1] += "n"    # or "rn" on windows

            file.write(' '.join(line))





change_value(2, 1, 7.84)

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly : change_value(2, 2, 7.84) File "run.py", line 7, in change_value lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

|
show 2 more comments

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

if columns in your file are splited by space:

def change_value(column, row, new_value):

    lines = 

    with open('table1.txt', 'r+') as file:

        for line in file:

            lines.append(line.rstrip().split())



        lines[row - 1][column - 1] = str(new_value)

        file.seek(0)

        for line in lines:

            line[-1] += "n"    # or "rn" on windows

            file.write(' '.join(line))





change_value(2, 1, 7.84)

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly : change_value(2, 2, 7.84) File "run.py", line 7, in change_value lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

|
show 2 more comments

if columns in your file are splited by space:

def change_value(column, row, new_value):

    lines = 

    with open('table1.txt', 'r+') as file:

        for line in file:

            lines.append(line.rstrip().split())



        lines[row - 1][column - 1] = str(new_value)

        file.seek(0)

        for line in lines:

            line[-1] += "n"    # or "rn" on windows

            file.write(' '.join(line))





change_value(2, 1, 7.84)

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly : change_value(2, 2, 7.84) File "run.py", line 7, in change_value lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

|
show 2 more comments

if columns in your file are splited by space:

def change_value(column, row, new_value):

    lines = 

    with open('table1.txt', 'r+') as file:

        for line in file:

            lines.append(line.rstrip().split())



        lines[row - 1][column - 1] = str(new_value)

        file.seek(0)

        for line in lines:

            line[-1] += "n"    # or "rn" on windows

            file.write(' '.join(line))





change_value(2, 1, 7.84)

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

if columns in your file are splited by space:

def change_value(column, row, new_value):

    lines = 

    with open('table1.txt', 'r+') as file:

        for line in file:

            lines.append(line.rstrip().split())



        lines[row - 1][column - 1] = str(new_value)

        file.seek(0)

        for line in lines:

            line[-1] += "n"    # or "rn" on windows

            file.write(' '.join(line))





change_value(2, 1, 7.84)

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

edited Nov 23 '18 at 6:57

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

answered Nov 23 '18 at 6:30

Andrey Suglobov

1349

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly : change_value(2, 2, 7.84) File "run.py", line 7, in change_value lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

|
show 2 more comments

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly : change_value(2, 2, 7.84) File "run.py", line 7, in change_value lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

Thank you very much it works very well :D ! But how to manage the spaces in file.write()? if for example I want after 3 written values it to return to the line. so that I can find the initial columns.

– F.Moab
Nov 24 '18 at 16:39

I'am not complitly understand your question. Pleas tell litle more. in that example, you can get any line in lines list. line contain values of columns just do lines[index_of_line_you_want][index_of_column_you_want]. indexes is numirated from 0, that why in example I get it like [index - 1] do all manipulations with data you want after file is readed and before it writen.

– Andrey Suglobov
Nov 24 '18 at 17:59

how to return to the line all 3 values? because here the code works well but modifies the text file by writing all the values in succession. example : change_value(2, 1, 7.84) --> 1.007825 7.84 0.5 0.95 4.002603 0 0.5 0.05 ... We no longer see the columns in the file

– F.Moab
Nov 24 '18 at 20:36

now your columns are separated by spaces. betwin the quotes in ' '.join(line) you can set a separator of columns. it may be two spaces or any you want. The symbol t will set space betwin column aqual the one tab, if you want two - set ttand so on... if you will set non-spaced symbol like - or other, you shoud set same in previos ....split("your_separator_here") method to corect read and divide values from line. By defalt it seted to space. Hope it helps.

– Andrey Suglobov
Nov 24 '18 at 22:51

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly :

change_value(2, 2, 7.84)   File "run.py", line 7, in change_value     lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

Yes thank you so much ! but a other little problem, when I put row > 1 I have directly :

change_value(2, 2, 7.84)   File "run.py", line 7, in change_value     lines[row - 1][column - 1] = str(new_value) IndexError: list index out of range

– F.Moab
Nov 25 '18 at 4:29

|
show 2 more comments

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