从正则表达式创建所有组合

Question

I have sentences that define a template for random combinations:

I like dogs/cats    
I want to eat today/(the next day)

I tried using a regex:

m = re.search(r'(?P<list>[A-Za-z]+/([A-Za-z]+)+)', sentence)
words = m.group('list').split('/')
combs = [comb for comb in [sentence.replace(m.group('list'), w) for w in words]]

For the first sentence I get ['i like dogs', 'i like cats'] which is what I want. For the second sentence, re.search returns None . What I would like to get is ['I want to eat today', 'I want to eat the next day'] .

How do I need to change the regex?

Answer 1

(I want to eat today)*|(the next day)

Is the regex that will select the text you want...

Answer 2

r'(?P<list>[A-Za-z]+/([a-zA-Z]+|\\(.+?\\)))''

([a-zA-Z]+|\\(.+?\\)) matches strings like "word" or "(some word)". And it also matches "()", we need to remove heading "(" and trailing ")" using strip .

m = re.search(r'(?P<list>[A-Za-z]+/([a-zA-Z]+|\(.+?\)))', sentence)
words = m.group('list').split('/')
combs = [comb for comb in [sentence.replace(m.group('list'), w.strip('()')) for w in words]]

Answer 3

With below code you will get something like

> sentence = 'I want to eat today/(the next day)' m =
> re.search(r'(?P<list>[A-Za-z]+/([A-Za-z]+|(\(.*?\))))', sentence)
> print m.group('list') words = m.group('list').split('/') combs = [comb
> for comb in [sentence.replace(m.group('list'), w) for w in words]]
> print combs

['I want to eat today', 'I want to eat (the next day)'

you could dome extra processing to get rid of the extra parenthesis which should be easy