python re.split() to split by spaces, commas, and periods, but not in cases like 1,000 or 1.50

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I want to use python re.split() to split a string into individual words by spaces, commas and periods. But I don’t want "1,200" to be split into ["1", "200"] or ["1.2"] to be split into ["1", "2"].


l = "one two 3.4 5,6 seven.eight nine,ten"

The result should be ["one", "two", "3.4", "5,6" , "seven", "eight", "nine", "ten"]

Use a negative lookahead and a negative lookbehind:

> s = "one two 3.4 5,6 seven.eight nine,ten"
> parts = re.split('\s|(?<!\d)[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten']

In other words, you always split by \s (whitespace), and only split by commas and periods if they are not followed (?!\d) or preceded (?<!\d) by a digit.


EDIT: As per @verdesmarald comment, you may want to use the following instead:

> s = "one two 3.4 5,6 seven.eight nine,ten,1.2,a,5"
> print re.split('\s|(?<!\d)[,.]|[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten', '1.2', 'a', '5']

This will split "1.2,a,5" into ["1.2", "a", "5"].


So you want to split on spaces, and on commas and periods that aren’t surrounded by numbers. This should work:

r" |(?<![0-9])[.,](?![0-9])"

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