我有2个表达式应该是有效的没有被承认为

Question

import re 

cards1 = "'F'*4 + 'H'*10"; cards2 = 'FFHH' 
def find_number_of_cards(cards): 
    regexp = re.compile(r"(?P<FandH>[FH]+) | (('F')[*](?P<F>[0-9]+)\s*[+]\s*('H')[*](?P<H>[0-9]+))") 
    result = regexp.search(cards) 
    if result == None: 
     return ("The expression given is not valid.") 
    else: 
     FnH = result.group('FandH') 
     F = result.group('F') 
     H = result.group('H') 
     if FnH == None: 
      return F, H 
     else: 
      return "Blank." 

print(find_number_of_cards(cards1)) 
print(find_number_of_cards(cards2)) 

Answer 1

更改此：

regexp = re.compile(r"(?P<FandH>[FH]+) | (('F')[*](?P<F>[0-9]+)\s*[+]\s*('H')[*](?P<H>[0-9]+))") 

这样：

regexp = re.compile(r"(?P<FandH>[FH]+)|(('F')[*](?P<F>[0-9]+)\s*[+]\s*('H')[*](?P<H>[0-9]+))") 

它寻找字符串中的空间，这不在那里。