在字符串中查找數組中任何值的出現並將其打印出來

Question

我知道這將會是一件非常簡單的事情，但它只是對我而言不起作用。

INDICATORS = ['dog', 'cat', 'bird'] 
STRING_1 = 'There was a tree with a bird in it' 
STRING_2 = 'The dog was eating a bone' 
STRING_3 = "Rick didn't let morty have a cat" 


def FindIndicators(TEXT): 
    if any(x in TEXT for x in INDICATORS): 
     print x # 'x' being what I hoped was whatever the match would be (dog, cat) 

預期輸出：

FindIndicators(STRING_1) 
# bird 

FindIndicators(STRING_2) 
# dog 

FindIndicators(STRING_3) 
# cat 

相反，我得到了 'X' 的未解參考。我有一種感覺，一旦我看到答案，我就會面對辦公桌。

Answer 1

你誤解如何any()作品。它消耗你所給的任何東西，並返回True或False。之後不存在x。

>>> INDICATORS = ['dog', 'cat', 'bird'] 
>>> TEXT = 'There was a tree with a bird in it' 
>>> [x in TEXT for x in INDICATORS] 
[False, False, True] 
>>> any(x in TEXT for x in INDICATORS) 
True 

而是做到這一點：

>>> for x in INDICATORS: 
...  if x in TEXT: 
...   print x 
... 
bird 

Answer 2

如文檔中所描述的，任何返回一個布爾值，不匹配的列表。所有呼叫所做的就是表明至少存在一個「命中」。

可變X只存在內的發電機表達;它在後面排隊，所以你不能打印它。

INDICATORS = ['dog', 'cat', 'bird'] 
STRING_1 = 'There was a tree with a bird in it' 
STRING_2 = 'The dog was eating a bone' 
STRING_3 = "Rick didn't let morty have a cat" 


def FindIndicators(TEXT): 
    # This isn't the most Pythonic way, 
    # but it's near to your original intent 
    hits = [x for x in TEXT.split() if x in INDICATORS] 
    for x in hits: 
     print x 

print FindIndicators(STRING_1) 
# bird 

print FindIndicators(STRING_2) 
# dog 

print FindIndicators(STRING_3) 
# cat