如何同时要求整数和字符串

Question

print("welcome to the Pythagoras calculator")
print("please leave empty whenever asked for any sides of the triangle you do not have data for")
print("please answer every question with integers only")

side = input("which side would you like to be found?")

hyp = int(input("hypotenuse length:"))
if hyp == (''):
    hyp = str(hyp)
adj = int(input("adjacent length:"))
if adj ==(''):
    adj = str(adj)
opp = int(input("opposite length:"))
if opp == (''):
    opp = str(opp)

while hyp == ("") and adj == (""):
    print("you need to insert two values")
    hyp = int(input("hypotenuse length:"))
    adj = int(input("adjacent length:"))
    opp = int(input("opposite length:"))

while hyp == ("") and opp == (""):
             print("you need to insert two values")
             hyp = int(input("hypotenuse length:"))
             adj = int(input("adjacent length:"))
             opp = int(input("opposite length:"))

while adj == ("") and opp == (""):
             print("you need to insert two values")
             hyp = int(input("hypotenuse length:"))
             adj = int(input("adjacent length:"))
             opp = int(input("opposite length:"))

while adj == ("") and opp == (""):
             print("you need to insert two values")
             hyp = int(input("hypotenuse length:"))
             adj = int(input("adjacent length:"))
             opp = int(input("opposite length:"))

while hyp == ("") and adj == ("") and opp == (""):
             print("you need to insert two values")
             hyp = int(input("hypotenuse length:"))
             adj = int(input("adjacent length:"))
             opp = int(input("opposite length:"))

我正在尝试创建一个毕达哥拉斯计算器，但是当我要求人们插入边的长度时，它会弹出一个错误，说基本上我尝试使用int作为字符串（在验证中），我知道我不能使用int作为字符串，我只是不知道如何在同一个输入中同时使用字符串和整数（我要求）它是一个字符串和一个整数）。你知道吗

谢谢

Answer 1

您可以使用如图所示的try/except块，并添加其他条件进行验证（我检查了validate_input()中的空白边数，但可以扩展到正数，等等）。你知道吗

#!/usr/bin/python

import math

#Triangle has three sides; two can be defined and the third is calculated
class Triangle:

    def __init__(self):
        self.side={"adjacent":0,"opposite":0,"hypotenuse":0}

    def define_sides(self):
        for i in self.side:
            self.side[i]=self.get_side(i)

    def print_sides(self):
        for i in self.side:
            print "side",i,"equals",self.side[i]

    #return user integer or None if they enter nothing
    def get_side(self,one_side):
        prompt = "Enter length of "+one_side+": "
        try:
            return input(prompt)
        except SyntaxError:
            return None

    def count_nones(self):
        nones=0
        for side, length in self.side.iteritems():
            if self.side[side] == None:
                nones+=1
        return nones

    def validate_input(self):
        nNones=self.count_nones()

        if nNones < 1:
            print "You must leave one side blank."
            quit()
        if nNones > 1:
            print "Only one side can be left blank."

    def calculate_missing_length(self):
        h=self.side["hypotenuse"]
        a=self.side["adjacent"]
        o=self.side["opposite"]

        #hypotenuse is missing
        if h == None:
            self.side["hypotenuse"] = math.sqrt(a*a+o*o)

        #adjacent is missing
        if a == None:
            self.side["adjacent"] = math.sqrt(h*h-o*o)

        #opposite is missing
        if o == None:
            self.side["opposite"] = math.sqrt(h*h-a*a)

#begin program
triangle=Triangle()
triangle.define_sides()
triangle.print_sides()
triangle.validate_input()
triangle.calculate_missing_length()
triangle.print_sides()

Answer 2

在Python2.7中，您只需像

hyp = raw_input("hypotenuse length:")
adj = raw_input("adjacent length:")
opp = raw_input("opposite length:")

然后您的支票将工作，因为如果没有输入任何内容，它们将是空字符串。你知道吗

另外，您最好对所有输入使用raw_input，只要您需要值int，然后显式地转换它，如

temp = int(adj) 

raw_input()返回一个字符串，input()尝试将输入作为Python表达式运行。你知道吗

在python3中，raw_input只是重命名为input，因此可以直接使用它来获取字符串形式的输入。你知道吗