re.search in python, return a list of integers separated by comma-CodePudding

I have a list of strings as follows:

my_list = ['array("i", [12694499, 12855016, 123457])',
'array("i", [12694499, 12865016, 123457])',
'array("i", [12694499, 12855016])',
'array("i", [12699749, 12877477])',
'array("i", [12828285, 12868277])',
'array("i", [-1])',
'array("i", [-1])',
'array("i", [-1])']

I am a newbie using regular expressions in python and I'm trying to use re.search to extract the values in brackets and separated by commas. As follows:

[12694499, 12855016, 123457]
[12694499, 12865016, 123457]
[12694499, 12855016]
[12699749, 12877477]
[12828285, 12868277]
[-1]
[-1]
[-1]

I have tried this:

for value in my_list:
    coords = re.search(r"\[[0-9] ,\s[0-9] \]", value)
    print(coords)

but I get this:

None
None
None
None
None
None
None
None

I know I can use split() to get the numbers, but I'm really interested in understand how RE works in python.

Any suggestion would be much appreciated!

CodePudding user response：

Your code actually has a match for the 3rd, 4th and 5th item.

But if you want to get all the matches, you can use an optional hyphen -? and optionally repeat the part with the comma and the digits (?:,\s-?[0-9] )*

Then first check the result of re.search and print the value with .group()

for value in my_list:
    coords = re.search(r"\[-?[0-9] (?:,\s-?[0-9] )*]", value)
    if coords:
        print(coords.group())

Output

[12694499, 12855016, 123457]
[12694499, 12865016, 123457]
[12694499, 12855016]
[12699749, 12877477]
[12828285, 12868277]
[-1]
[-1]
[-1]

See a Python demo.