I want to split a string separated by commas not inside Matrix expression. For example:
input:
value = 'MA[1,2],MA[1,3],der(x),x,y'
expected output:
['MA[1,2]','MA[1,3]','der(x)','x','y']
I tried with value.split(','), but it splits inside [], I tried with some regular expressions to catch extract text inside [] using this regular expression
import re
re.split(r'\[(.*?)\]', value)
I am not good in regular expression,Any suggestions would be helpful
You can use negative lookbehind
>>> import re
>>> value1 = 'MA[1,2],MA[1,3],der(x),x,y'
>>> value2 = 'M[a,b],x1,M[1,2],der(x),y1,y2,der(a,b)'
>>> pat = re.compile(r'(?<![[()][\d\w]),')
>>> pat.split(value1)
['MA[1,2]', 'MA[1,3]', 'der(x)', 'x', 'y']
>>> pat.split(value2)
['M[a,b]', 'x1', 'M[1,2]', 'der(x)', 'y1', 'y2', 'der(a,b)']
"(?<![[()][\d\w]),"g
(?<![[()][\d\w]) Negative Lookbehind - Assert that it is impossible to match the regex below
[[()] match a single character present in the list below
[() a single character in the list [() literally[\d\w] match a single character present in the list below
\d match a digit [0-9]
\w match any word character [a-zA-Z0-9_], matches the character , literally
g modifier: global. All matches (don't return on first match)
