python - 检查字符串列表中的字符是否是另一个字符串列表中的字符的子集

Question

给出以下列表:

list1 = ["Box", "Stall"]
list2 = ["Ball", "Sox"]

如何检查组成“Ball”和“Sox”(“BallSox”)的所有字符是否都包含在“BoxStall”(组成“Box”和“Stall”的字符)中？他们就是这样。必须区分大小写。

我尝试在 if 语句中使用 list() 命令，检查“B​​ox”的所有字符是否都在 list2 内，但看起来似乎是这样必须更复杂一点。

Answer 1

我认为没有内置函数可以处理这个问题。你能做的是

# put all characters of first list into a dictionary 
# object.  This is easier to use for looking up characters
# later
list_chars = {}
for string in list1:
    for char in string:
        list_chars[char] = True


# run through second list, for each character
# in the other list, check if it exists in
# the dictionary of characters from the first 
# list.  If it does not, then set missing_character to True.
missing_character = False
for string in list2:
    for char in string:
        if not list_chars.get(char,False):
            # means that the first list does
            # not contain the character char
            missing_character = True


# print whether one list was actually missing a character.
if missing_character:
   print('Missing some character!')
else
   print('Contained all characters!')

如果上述某些部分没有意义，请随时提出后续问题。另外，如果您使用上面的break语句，您可以使上面的代码更快一点。 (如果您已经知道列表缺少一个字符，请尽早退出 for 循环。)我会将其留给您进行推理并确定您是否感兴趣。