如何修复此Python elif语句语法错误？

我试图用Python编写一个计算器来计算公式，但我的elif语句出现语法错误。我已经在这里和其他网站上查看了一些其他帖子，但似乎人们犯的错误与我不同。提前感谢您的帮助！：）这是我的密码：

# IMPORTS

import os
import math

# SELECTION

print ("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
print ("~~~ PYTHAGOREAN THEOROM CALCULATOR ~~~")
print ("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
print ("OPTIONS:")
print ("1 - SOLVE FOR HYPOTENUSE")
print ("2 - SOLVE FOR LEG")
print ("3 - SOLVE FOR LEG 2")

user_choice = input("ENTER YOUR CHOICE: ")

# HYPOTENUSE MATHEMATICS

if user_choice == "1":
    firstnh = int(input("ENTER YOUR FIRST LEG'S DIMENSION: "))
    secondnh = int(input("ENTER YOUR SECOND LEG'S DIMENSION: "))

secondsteph = (firstnh ** 2 + secondnh **2)

hanswer = math.sqrt(secondsteph)

print (hanswer , "IS YOUR ANSWER")

input()
os.system('cls')

# LEG 1 MATHEMATICS

elif user_choice == "2":
    firstnl = int(input("ENTER YOUR LEG: "))
    secondnl = int(input("ENTER YOUR HYPOTENUSE: "))

secondstepl = (secondnl ** 2 - firstnl ** 2)

lanswer = math.sqrt(secondstepl)

print (lanswer, "IS YOUR ANSWER")

input()
os.system('cls')

错误在这里：

# LEG 1 MATHEMATICS

elif user_choice == "2":  < - - - ERROR HERE
    firstnl = int(input("ENTER YOUR LEG: "))
    secondnl = int(input("ENTER YOUR HYPOTENUSE: "))

secondstepl = (secondnl ** 2 - firstnl ** 2)

lanswer = math.sqrt(secondstepl)

print (lanswer, "IS YOUR ANSWER")

input()
os.system('cls')

---

问题在于if和elif子句之间的未插入代码：

secondsteph = (firstnh ** 2 + secondnh **2)

hanswer = math.sqrt(secondsteph)

print (hanswer , "IS YOUR ANSWER")

input()
os.system('cls')

---

if和elif必须处于同一缩进级别：

if <condition>:
    something
elif <condition>:
    somethingelse

---

您的用法错误，

elif

语句只能在if语句之后使用

if user_choice == "1":
    firstnh = int(input("ENTER YOUR FIRST LEG'S DIMENSION: "))
    secondnh = int(input("ENTER YOUR SECOND LEG'S DIMENSION: "))

此部分仅在

if

语句中。 从第

secondsteph=（firstnh**2+secondnh**2）

行开始，它是一个新的代码块，不在if块中。如果这是缩进错误，请尝试：

if user_choice == "1":
    firstnh = int(input("ENTER YOUR FIRST LEG'S DIMENSION: "))
    secondnh = int(input("ENTER YOUR SECOND LEG'S DIMENSION: "))

    secondsteph = (firstnh ** 2 + secondnh **2)

    hanswer = math.sqrt(secondsteph)

    print (hanswer , "IS YOUR ANSWER")

    input()
    os.system('cls')

# LEG 1 MATHEMATICS

elif user_choice == "2":
    firstnl = int(input("ENTER YOUR LEG: "))
    secondnl = int(input("ENTER YOUR HYPOTENUSE: "))

如果没有，请填写声明

secondsteph = (firstnh ** 2 + secondnh **2)

hanswer = math.sqrt(secondsteph)

print (hanswer , "IS YOUR ANSWER")

input()
os.system('cls')

---

在

elif

块之后

不能有

if

语句，在该

if

语句之外执行常规语句，然后用

elif

扩展

if

。在

if

语句后将特定于第一种情况的代码放入块中（缩进相关！）并在

if

-

elif

-

else

结构之后放置在任何情况下都要执行的常规代码。

elif

应位于

if

语句旁边。在

if

之后有中间代码，它不是

if

的一部分。而且艾利夫可以直接跟我打招呼，我想说谢谢你的帮助，我真的很感激。起初我不明白，但一旦我开始思考清楚，一切就变得明朗起来。我还要感谢所有做出贡献的人。祝您今天过得愉快！（我甚至还学到了一点我正在使用的八年级代数公式哈哈）这是一个缩进错误，我只需要缩进到额外的代码中。谢谢你的帮助！我很感激。

if user_choice == "1":
    firstnh = int(input("ENTER YOUR FIRST LEG'S DIMENSION: "))
    secondnh = int(input("ENTER YOUR SECOND LEG'S DIMENSION: "))

if user_choice == "1":
    firstnh = int(input("ENTER YOUR FIRST LEG'S DIMENSION: "))
    secondnh = int(input("ENTER YOUR SECOND LEG'S DIMENSION: "))

    secondsteph = (firstnh ** 2 + secondnh **2)

    hanswer = math.sqrt(secondsteph)

    print (hanswer , "IS YOUR ANSWER")

    input()
    os.system('cls')

# LEG 1 MATHEMATICS

elif user_choice == "2":
    firstnl = int(input("ENTER YOUR LEG: "))
    secondnl = int(input("ENTER YOUR HYPOTENUSE: "))

secondsteph = (firstnh ** 2 + secondnh **2)

hanswer = math.sqrt(secondsteph)

print (hanswer , "IS YOUR ANSWER")

input()
os.system('cls')