我的循环缩进看起来很奇怪，这正常吗？ (python 2)

Question

我正在尝试在满足某些条件时创建循环，到目前为止它可以工作，但是当我尝试创建更多条件时，我必须进一步缩进它们以使我的程序工作。

def terrain(surface):
    surface = raw_input("What surface will you be driving on? ")
    while surface != "ice" and surface != "concrete" and surface != "soil" and surface != "asphalt" :
        surface = raw_input("Surface not valid. Please enter a valid surface: ")
    if surface == "ice":
                u = raw_input("what is the velocity of the car in meters per second? ")
                u = int(u)
                while int(u) < 0:
                    u = raw_input("Velocity must be a positive integer: ")
                                while int(u) == 0:
                                    u = raw_input("Velocty must be a number greater than zero: ")
                        while int(u) > 72:
                                                                u = raw_input("This vehicle cannot reach this speed: ")
                a = raw_input("How quickly is the vehicle decelerating? ")
                a = int(a)
                while int(a) > 0:
                    a = raw_input("Deceleration cannot be a positive integer: ")
                else: 
                        s1 = u**2
                        s2 = 2*.08*9.8
                    s = s1/s2
                    print "This is how far the vehicle will travel on ice: "
                    print ("The vehicle will travel %i meters before coming to a complete stop" % (s))
terrain("ice")

我只是希望能够创建更多没有乱七八糟的缩进的循环

Answer 1

以下是我的理解，如有错误请评论：
1.获取表面值
2. if (surface is invalid) 要求另一个值
3. 如果（表面是冰）：
一种。获得你的价值
b.获取 a
的价值 C。使用公式
计算 s s1 = u**2
s2 = 2*.08*9.8
s = s1/s2
d.显示 4. 如果表面不是冰，则什么也不做（根据您发布的代码，但可以对其进行编辑以具有类似的块，例如 if surface == "soil" ）如果是那么

def terrain():
    surface = raw_input("What surface will you be driving on? ")
    valid_surface = ["ice", "concrete", "soil", "asphalt"]
    while surface not in valid_surface:
        surface = raw_input("Surface not valid. Please enter a valid surface: ")
    if surface == "ice":
        u = raw_input("what is the velocity of the car in meters per second?")
        while int(u) < 0:
            u = raw_input("Velocity must be a positive integer: ")
        while int(u) == 0:
            u = raw_input("Velocty must be a number greater than zero: ")
        while int(u) > 72:
            u = raw_input("This vehicle cannot reach this speed: ")
        a = raw_input("How quickly is the vehicle decelerating? ")
        a = int(a)
        while int(a) > 0:
            a = raw_input("Deceleration cannot be a positive integer: ")
        while int(a) < -55: #note all while blocks are at same level
            #Do stuff  #contents inside while is indented by 4 spaces
            a = raw_input("This vehicle cannot have this deceleration. Please input another value: ")

        s1 = u**2
        s2 = 2*.08*9.8
        s = s1/s2
        print "This is how far the vehicle will travel on ice: "
        print ("The vehicle will travel %i meters before coming to a complete stop" % (s))

我通常定义这样一个函数：

def get_int(prompt, error):
    variable = input(prompt)
    while True:
        try:
            variable = int(variable) 
        except ValueError:
            variable = input(error)
            continue
        break
    return variable

并将其用作：

v1 = get_int("Enter value for accn: ", "Please input integer: ")
v2 = get_int("Enter value for velocity: ", "Please input integer: ")

如果您需要接受浮动（例如 1.25）值，您可能需要更改某些内容，例如将 variable = int(variable) 更改为 variable = float(variable)。

Answer 2

你的代码有很多问题，我会指出其中的一些。你也应该开始使用 python3.x 而不是 python2 您可以直接将从用户那里获取的输入解析为 int(raw_input("xyz"))
牢记以上所有内容，下面的代码应该可以工作

import sys

def terrain():
    surface = raw_input("What surface will you be driving on? ")
    vel = -1
    while surface != "ice" and surface != "concrete" and surface != "soil" and surface != "asphalt" :
        surface = raw_input("Surface not valid. Please enter a valid surface: ")
    if surface == "ice":
        vel = int(raw_input("what is the velocity of the car in meters per second? "))
    while vel < 0:
        vel = int(raw_input("Velocity must be a positive integer: "))
    while vel == 0:
        vel = int(raw_input("Velocty must be a number greater than zero: "))
    while vel > 72:
        vel = int(raw_input("This vehicle cannot reach this speed: "))
    acc = int(raw_input("How quickly is the vehicle decelerating? "))
    while acc > 0:
        acc = int(raw_input("Deceleration cannot be a positive integer: "))

    s1 = vel**2
    s2 = 2*.08*9.8
    s = s1/s2
    print ("This is how far the vehicle will travel on ice: ")
    print ("The vehicle will travel %i meters before coming to a complete stop" % (s))

terrain()

了解缩进在 python 中的工作原理，因为它们是开始新代码块的方式，并尝试在我为您格式化的代码之上添加更多条件，然后您就会明白更好。

Answer 3

无论何时缩进，都应始终添加相同数量的缩进。没有必要在一个地方使用 4 个空格的缩进，而在其他地方使用 12 个空格。最常见的约定是使用 4 个空格。
仅在开始新块时添加缩进级别，即以冒号结尾的行之后的行。
结束一个块时，以下行必须与开始该块的关键字对齐。当然，如果不止一个块同时结束，这可能意味着缩进不止一层。

如果没有与缩进相关的语法错误，您的代码可能如下所示：

def terrain(surface):
    surface = raw_input("What surface will you be driving on? ")
    while surface != "ice" and surface != "concrete" and surface != "soil" and surface != "asphalt" :
        surface = raw_input("Surface not valid. Please enter a valid surface: ")
    if surface == "ice":
        u = raw_input("what is the velocity of the car in meters per second? ")
        u = int(u)
        while int(u) < 0:
            u = raw_input("Velocity must be a positive integer: ")
            while int(u) == 0:
                u = raw_input("Velocty must be a number greater than zero: ")
            while int(u) > 72:
                u = raw_input("This vehicle cannot reach this speed: ")
        a = raw_input("How quickly is the vehicle decelerating? ")
        a = int(a)
        while int(a) > 0:
            a = raw_input("Deceleration cannot be a positive integer: ")
        else: 
            s1 = u**2
            s2 = 2*.08*9.8
            s = s1/s2
            print "This is how far the vehicle will travel on ice: "
            print ("The vehicle will travel %i meters before coming to a complete stop" % (s))
terrain("ice")

我的循环缩进看起来很奇怪，这正常吗？ (python 2)

My indents for my loops look strange, is this normal? (python 2)

python

if-statement

indentation

while-loop

python-2.7