Question

我正在创建一个简单的计算器程序，并希望缩短在检查输入变量时我必须做的输入量。有没有办法分配我的IF / ELSE语句并调用它们以节省时间和打字？我必须写出很多变量。我还没有很多关于python的知识，所以请尽量使它变得简单易懂。

loop = 1
while loop == 1:
    a1 = input("Add this number of apples: ")
    if a1.isdigit():
        a1 = int(a1)
    else:
        print("You cannot add a letter, changed to 0.")
        a1 = 0
        loop = 1
    if a1 < 0:
        print(user_name + ", You cannot choose a negative number!")
        loop = 1
    else:
        print("")
        print(a1, "apples +", a2, "apples =", a1 + a2, "total apples.")
        print("")
        loop = 1
    a2 = input("to this number of apples: ")
    if a2.isdigit():
        a2 = int(a2)
    else:
        print("You cannot add a letter, changed to 0.")
        a2 = 0
        loop = 1
    if a2 < 0:
        print(user_name + ", You cannot choose a negative number!")
        loop = 1
    else:
        print("")
        print(a1, "apples +", a2, "apples =", a1 + a2, "total apples.")
        print("")
        loop = 1

Answer 1

def get_int(prompt):
    while True:
        try:
            return int(raw_input(prompt))
        except ValueError:
            print "Please Enter An Integer"

def get_conditional_int(prompt,condition,error):
    while True:
          a = get_int(prompt)
          if condition(a):
             return a
          print error


a = get_conditional_int("Enter The Number Of Apples:",lambda x:x>0,"Enter A Positive Value!")
print a + 54

作为您现有代码的旁白，您永远不会得到负面的

print "-5".isdigit()

如何在Python中创建变量检查？

1 个答案: