使用 elif 语句 \"print function\" 不能正常工作，而不是打印 if 语句\"print function\"

Answer 1

您需要像这样使用== 运算符：

import random

print("Project Select")
print("")
#for future me
print("Summary Of Project: This Project Has The Goal To Help Select What Anime I Should Watch Next")
print("")
Anime = ["Black Bullet","Princess Connect","Overlord","Date A Live", "Chivalry of a failed knight", "The Detective Is Already Dead",
"Shimoneta", "I'm Quitting Heroing","The Greateast Mage"]

selector = random.choice(Anime)

print(selector)

if selector == "Black Bullet":
    print("Banana 1")
elif selector == "Princess Connect":
    print("Watermelon 2")
elif selector == "Overlord":
    print("Strawberry 3")
elif selector == "Date A Live":
    print("kiwi 4")
elif selector == "Chivalry Of A Failed Knight":
    print("apple 5")
elif selector == "The Detective Is Already Dead":
    print("blueberry 6")
elif selector == "Shimoneta":
    print("lemon 7")
elif selector == "I'm Quitting Heroing":
    print("cherry 8")
else:
    print("orange 9")

这就是您的代码不起作用的原因：

对于 if - elif 语句，您有：

if("Black Bullet"):
    print("Banana 1")
elif("Princess Connect"):
    print("Watermelon 2")
elif("Overlord"):
    print("Strawberry 3")
elif("Date A Live"):
    print("kiwi 4")
elif("Chivalry Of A Failed Knight"):
    print("apple 5")
elif("The Detective Is Already Dead"):
    print("blueberry 6")
elif("Shimoneta"):
    print("lemon 7")
elif("I'm Quitting Heroing"):
    print("cherry 8")
else:
    print("orange 9")

这告诉 Python：“如果"Black Bullet" 的布尔值等于True，则执行print("Banana 1")，否则，如果布尔值...”等等。

字符串的布尔值为False 的唯一方法是当字符串为空时，所以你明白为什么代码只打印Banana 1。

Answer 2

这是 Python 3.x（简称 Python3）的语法示例。顺便说一句，您有错字“失败骑士的骑士精神”应该是“失败骑士的骑士精神”

import random

print("Project Select")
print("")
#for future me
print("Summary Of Project: This Project Has The Goal To Help Select What Anime I Should Watch Next")
print("")
Anime = ["Black Bullet", "Princess Connect", "Overlord", "Date A Live", "Chivalry Of A Failed Knight", "The Detective Is Already Dead",
"Shimoneta", "I'm Quitting Heroing", "The Greateast Mage"]

selector = random.choice(Anime)

print(selector)

if selector == "Black Bullet":
    print("Banana 1")
elif selector == "Princess Connect":
    print("Watermelon 2")
elif selector == "Overlord":
    print("Strawberry 3")
elif selector == "Date A Live":
    print("kiwi 4")
elif selector == "Chivalry Of A Failed Knight":
    print("apple 5")
elif selector == "The Detective Is Already Dead":
    print("blueberry 6")
elif selector == "Shimoneta":
    print("lemon 7")
elif selector == "I'm Quitting Heroing":
    print("cherry 8")
elif selector == "The Greateast Mage":
    print("orange 9")
else:
    print("Not Found!")

输出：

Project Select

Summary Of Project: This Project Has The Goal To Help Select What Anime I Should Watch Next

The Detective Is Already Dead
blueberry 6

如果字符串不是 ("") 为空，则 if 语句将给出真值。例如：

if("helloworld"):
    print("yes")    #yes

if(""):
    print("yes")    #no output

Answer 3

这个问题是你的第一个if 语句将始终评估为True，并导致该块内缩进的代码运行。非空字符串计算为True：

>>> bool("")
False
>>> bool("hello")
True

要解决您的问题，您需要检查selector 的相等性，这将包含random.choice(Anime) 返回的任何内容。这是一个简单的例子：

>>> import random
>>> def foo(lst):
...     rand = random.choice(lst)
...     if rand == 1:
...         print("1 is the element")
...     elif rand == 2:
...         print("2 is the element")
...     elif rand == 3:
...         print("3 is the element")
...
>>> foo([1, 2, 3])
1 is the element
>>> foo([1, 2, 3])
2 is the element
>>> foo([1, 2, 3])
2 is the element
>>> foo([1, 2, 3])
1 is the element
>>> foo([1, 2, 3])
3 is the element

Answer 4

作为所提供答案的替代方案，您可能希望使用字典将名称与食物相关联。

assoc = {
  'Black Bullet':                  'Banana 1',
  'Princess Connect':              'Watermelon 2',
  'Overlord':                      'Strawberry 3',
  'Date A Live':                   'kiwi 4',
  'Chivalry Of A Failed Knight':   'apple 5',
  'The Detective Is Already Dead': 'blueberry 6',
  'Shimoneta':                     'lemon 7',
  'I\'m Quitting Heroing':         'cherry 8'
}

现在您可以简单地：

print(assoc.get(selector, 'Not found!'))

使用assoc.get(selector, 'Not found!') 而不是assoc[selector] 可以让我们提供一个默认值，以便在字典中找不到索引时返回，从而替换 if/elif/else 语句中的else。

如果您需要获取所有名称，则可以使用：

list(assoc.keys())