如何检查 python 中字符串中的这个或那个字符？

Question

When I used only a string or character to check occurrence in string then it works fine but when I used two strings ("a" or "b" in string) then it doesn't work

lst =["test in a", "test in b" "test b in a", "a test b", "test"]

for i in lst:
   if("a" or "b" in lst):
      print("true")
   else:
      print("false")

expected result:

true

true

true

true

false

Answer 1

try this,

lst =["test in a", "test in b" "test b in a", "a test b", "test"]

    for i in lst:
       if any(item in i for item in ['a', 'b']):
          print("true")
       else:
          print("false")

Answer 2

You don't even need brackets,

if "a" in i or "b" in i:

Answer 3

You could shrink this to one line using list comprehensions as follows:

lst =["test in a", "test in b" "test b in a", "a test b", "test"]
test = [True if (("a" in i) or ("b" in i)) else False for i in lst]

I personally prefer lambdas for situations like these:

# This is written a bit wide, my style for these sort of things
f = lambda x: True if "a" in x else True if "b" in x else False
test = [f(i) for i in lst]

Answer 4

Firstly, you're missing a comma , in your list. Once fixed that, try this:

>>> lst =["test in a", "test in b", "test b in a", "a test b", "test"]
>>> test_set = {'a', 'b'}
>>> for text in lst :
...     print len(test_set & set(text)) > 0
... 
True
True
True
True
False

Answer 5

It's a simple typo.

You should do if("a" in i or "b" in i): instead of if("a" or "b" in lst): .