无论字符串是否在列表中，始终输出“不在列表中”

Question

I cannot figure out why the output is always "is not in the list" even when I enter a string that is in the list. I have checked if the variables are passing properly into the LinearSearch function and don't think it has anything to do with my syntax (though I may be wrong). New to programming and this is my first question on stackoverflow so don't be too harsh on me. :)

The Code:

def main():
    NameList = []
    found = bool
    for Index in range(0, 4):
        NameList.append(str(input("Enter a name: ")))
    SearchName = input("Please enter the name you want to search for: ")
    found = LinearSearch(NameList, SearchName)
    if found == True:
        print(SearchName,"is in the list.")
    elif found == False:
        print(SearchName,"is not in the list.")

def LinearSearch(NameList, SearchName):
    for Index in range(0, 4):
        if SearchName == NameList[Index]:
            return True
        else:
            return False

main()

Answer 1

Your LinearSearch function is returning False if the first name in the list is not the name you're searching for. You have to let it finish looping over the rest of the list, then return False if the name was never found.

def LinearSearch(NameList, SearchName):
    for Index in range(0, 4):
        if SearchName == NameList[Index]:
            return True
    return False

One improvement you can make to your code is to search through the entire list no matter how long it is, instead of only looking at the first four indices:

def LinearSearch(NameList, SearchName):
    for name in NameList:
        if SearchName == name:
            return True
    return False

(I don't know if the point of the exercise was to write LinearSearch , but that can be significantly shortened using Python's in operator instead.)