如何在Python / Spyder 2.7中比較字符串與列表列表

Question

我有一個清單：

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

和比較字符串myStr = 'first'

如果myStr存在於myList中，我想返回True ，否則返回False 。

Answer 1

僅針對您顯示的簡單示例，運行

[myStr] in myList

但是，如果每個子列表僅包含一項，則應該使myList等於一個平面列表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)

無論如何，該數組毫無意義：如果每個子數組只有一個元素，則應該使它更容易：

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

Answer 3

您只需要使用for循環遍歷列表一次，以便可以訪問子列表

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)