How to delete all characters after a "==" in each line of a file and update the file, using python script?

Question

I have a huge list of python packages that had been installed saved with the version numbers in the file "foo.txt", I want to delete the "==" and whatever after that in each lines, and save the file.

example text in the file:

autopep8==1.5.3
beautifulsoup4==4.8.2
bleach==3.1.4
bumpversion==0.5.3
... etc

Does this answer your question? [Split a string by a delimiter in python](https://stackoverflow.com/questions/3475251/split-a-string-by-a-delimiter-in-python) — mkrieger1, Jun 28 '20 at 06:24
@mkrieger1 not actually but thanks for your comment, it helped me in different way, but still it is important to get answers for my question — Older version of me, Jun 28 '20 at 07:41
whoever has the privileges to remove negative point on this question, please do it(but if need more edit, please let me know). — Older version of me, Aug 10 '21 at 22:02

Astik Gabani · Answer 1 · 2020-06-28T08:17:26.093

-1

Use the below code.

read that file and store it in list named pkg_list.

output_lst = []
with open("input.txt", "r") as f:
    input_data = f.readlines()
    output_lst = [name.split("==")[0] for name in input_data]

with open("input.txt", "w") as f:
    for pkg in output_lst:
        f.write("{}\n".format(pkg))

edited Jun 28 '20 at 08:17

answered Jun 28 '20 at 06:23

Astik Gabani

599
1
4
11

NameError: name 'pkg_list' is not defined – Older version of me Jun 28 '20 at 06:40
thanks for the update but the code is not affecting anything of the file – Older version of me Jun 28 '20 at 07:42
do you like to update the file as well? I just wrote a logic. Updated it – Astik Gabani Jun 28 '20 at 08:03
Updated the post. Verify it. – Astik Gabani Jun 28 '20 at 08:08
thanks, I think the dictionary [0] should be empty, shouldn't be? – Older version of me Jun 28 '20 at 08:11
For which dictionary are you talking? didn't get you. There is no such dictionary in solution. – Astik Gabani Jun 28 '20 at 08:13
it writes but became one line without spaces like following: aliyun-smsappdirsasgirefastroidautopep8beautifulsoup4bleachbumpversioncertificffichardetclickcodecovcolorclasscolorfulcoveragecryptographydefusedxmldistlibDjangodjango-allauthdjango-bleachdjango-colorfuldjango-contrib-commentsdjango-countriesdjango-djconfigdjango-el-paginationdjango-extensionsdjango-haystackdjango-infinite-scroll-paginationdjango-ipwaredjango-js-assetdjango-modelclusterdjango-modeltranslationdjango-mpttdjango-social-sharedjango-spiritdjango-taggitdjango-treebearddjango-widge – Older version of me Jun 28 '20 at 08:13
Updated the post again. Please verify – Astik Gabani Jun 28 '20 at 08:17
sorry I meant list, but the code worked, can you explain please – Older version of me Jun 28 '20 at 08:31
the latest update adds new line, but the entire file is empty, didn't fetch the texts from each lines to each new line, by the way, can be on one line but should get spaces in between them – Older version of me Jun 28 '20 at 08:35
Actually, after splitting the string, 1st element will be the package name here. So we created the list of all these packages. After that, we loop over the list and write back to the file – Astik Gabani Jun 28 '20 at 08:36
I think I made it, the last line update should be like -- f.write(pkg + " ") ------- – Older version of me Jun 28 '20 at 08:37
Yes, that's you need to do for space. – Astik Gabani Jun 28 '20 at 08:38
this answer shouldn't be marked with negative points..! – Older version of me Aug 10 '21 at 22:03

score -1 · Answer 2 · answered Jun 28 '20 at 06:34

-1

Use this line of code if you want to create a new file with updated data, if you want to just read use the data then make changes accordingly.

def read_write_file(input_path, output_path):
    with open(input_path, "r") as input_file:
        content = input_file.readlines()

    with open(output_path, 'w') as output_file:
        for line in content:
            line = line[:line.find('==')]
            output_file.write(line + '\n')

answered Jun 28 '20 at 06:34

Kuldeep Singh

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tried but not changing anything, can you explain your code please – Older version of me Jun 28 '20 at 08:08
how are you calling this? you need to call read_write_file functions with two arguments: 1. input file path (absolute path), 2. Absolute file name where exactly you want to save after change. Explanation: First with is opening you input file in read mode and keeping all your input lines in 'content' variable. Second with is opening file in write mode. for loop is iterating over all lines in content and then next line is slicing line from index 0 to index of '==' and assigning it back to line. Then next line is writing line to output file. (line.find with return you start index of '=='). – Kuldeep Singh Jun 29 '20 at 19:11
make sure paths are files not the directories and absolute paths. – Kuldeep Singh Jun 29 '20 at 19:12

How to delete all characters after a "==" in each line of a file and update the file, using python script?

2 Answers2