在字典上強制使用大小寫以比較Python中的用戶輸入

Question

我正在制作用戶輸入決策樹，我想強制將要比較輸入的字典轉換為小寫形式。 我在各個地方放置了.lower（）並不斷出錯。

not_found = True
while True:
    if OPTIONS == "1" or 'a':
        ARTIST_PICK = str(raw_input(
            "Please pick an artist\n"
            "Or Q to quit: ")).lower
        print ARTIST_PICK

        **entries = allData(filename).data_to_dict()
        for d in entries:
            arts = d['artist']**

        if ARTIST_PICK in arts:
            print "found it"

        elif ARTIST_PICK == 'q':
            break

        else:
            print "Sorry, that artist could not be found. Choose again."
            not_found = False

這是我要降低的“條目”樣本，並將用戶輸入與以下內容進行比較：

[{'album': 'Nikki Nack', 'song': 'Find a New Way', 'datetime': '2014-12-03 09:08:00', 'artist': 'tUnE-yArDs'},]

Answer 1

如果您的問題只是比較藝術家的姓名，則可以使用列表推導使所有內容變為小寫。

entries = allData(filename).data_to_dict()

if ARTIST_PICK in [ d['artist'].lower() for d in entries ]:
    print("found it")
elif ARTIST_PICK == "q":
    break
else
    print("Sorry, that artist could not be found. Choose again.")

或者，如果您更喜歡使用for循環（為便於閱讀而for了一些重新安排）：

if(ARTIST_PICK != 'q'):
    entries = allData(filename).data_to_dict()

    found = False

    for d in entries:
        if ARTIST_PICK == d['artist'].lower():
            found = True
            break
        elif ARTIST_PICK == "q":
            break

    if(found):
        print("found it")
    else:
        print("Sorry, that artist could not be found. Choose again.")
else:
    # handle the case where the input is 'q' here if you want

順便說一句，原則上，您應該將布爾變量命名為好像在句子中使用它們一樣。 如果找不到變量，則不要將變量not_found設置為False而是將名為found的變量設置為False或將not_found設置為True 。 從長遠來看使事情變得容易。

Answer 2

ARTIST_PICK = str（raw_input（“請選擇一個藝術家\\ n”“或Q退出：”））。lower（）