如何在Python / Spyder 2.7中比较字符串与列表列表

Question

我有一个清单：

myList = [['first'],['second'], ['third']]

和比较字符串myStr = 'first'

如果myStr存在于myList中，我想返回True ，否则返回False 。

Answer 1

仅针对您显示的简单示例，运行

[myStr] in myList

但是，如果每个子列表仅包含一项，则应该使myList等于一个平面列表myList = ['first', 'second', 'third']

那你只需要

myStr in myList

Answer 2

在Python 2.7中：

str = "first"
array = [["first"], ["second"], ...]
def isInArray(string, array):
    for subarray in array:
        for element in subarray:
            if element == string:
                return True
    return False
print isInArray(str, array)

无论如何，该数组毫无意义：如果每个子数组只有一个元素，则应该使它更容易：

array = ["first", "second", ...]

Answer 3

您只需要使用for循环遍历列表一次，以便可以访问子列表

myStr = 'first'
myList = [['first'],['second'], ['third']]

def str_in_list_of_lists(myStr, myList):
    for i in myList:
        if myStr in i:
            return True
    return False
print str_in_list_of_lists(myStr, myList)

Python 2.7中的示例：

food = [["apples", "prunes", "peaches"], ["tea", "coffee", "milk"], ["biscuits", "bread", "chips"]]

*You can try different strings here to check True/False values*

find = raw_input("What do you want in food?")

def str_in_list_of_lists(a, b):
    for i in food:
        if find in i:
            return True
    return False
print str_in_list_of_lists(find, food)