Question

我是Python 3的初学者。我试图将输出打印为整数或浮点数，具体取决于使用的类型。我怎么能够格式化代码，这样如果他们输入3作为半径输出“3”，如果他们输入3.5，它会输出半径为“3.5”？有什么建议吗？

print("Do you want to find the area of a circle? ")
again=input("Enter 'y' for yes, or enter 'n' to exit the program: ")

while (again=='y'):
    pi = 3.14
    radius = raw_input(" Input the radius of the circle: ")

    area = pi * radius * radius
    print("A circle with a radius of " + str(float(radius)) + " has an area of " +  "{0:.2f}".format(area))
    print()
    print("Would you like to run another? ")
    again = input("Enter 'y' to run another, enter 'n' to exit: ")

print("Have a nice day :) ")

Answer 1

用于调试或只是知道您可以使用的值的类型

print(type(some_var))

是否要在if语句中使用isinstance函数

if isinstance(radius, int):
   print("int")
if isinstance(radius, float):
    print("float")

这里有更多信息 Differences between isinstance() and type() in python

Answer 2

首先，一些事情：

＆＃34;输入＆＃34;之间的区别和＆＃34; raw_input＆＃34;是输入将返回一个数字值而raw_input将返回一个字符串值。如果您打算在数值运算中使用raw_input，则必须将其转换为int或float。同样，如果您希望用户输入单词或短语，则必须使用raw_input。

其次，print function将输出自动放在新行上。如果您想在输出中添加另一个新行，请使用＆＃39; \ n＆＃39;在你的字符串中。

最后，将半径转换为浮点数确保它将作为浮点打印出来。如果你在将它转换为字符串之前没有将它转换为浮点数，python将为你做格式化。

下面我拿了你的代码，注释掉了有缺陷的部分，并将我的修补程序直接放在它们下面：

print("Do you want to find the area of a circle? ")

# again = input("Enter 'y' for yes, or enter 'n' to exit the program: ")
again = raw_input("Enter 'y' for yes, or enter 'n' to exit the program: ")

while (again == 'y'):

    pi = 3.14

    # radius = raw_input(" Input the radius of the circle: ")
    radius = input("Input the radius of the circle: ")

    area = pi * radius * radius

    # print("A circle with a radius of " + str(float(radius)) + " has an area of " +  "{0:.2f}".format(area))
    print("A circle with a radius of " + str(radius) + " has an area of " +  "{0:.2f}".format(area))

    # print()
    # print("Would you like to run another? ")

    print("Would you like to run another? ")

    # again = input("Enter 'y' to run another, enter 'n' to exit: ")
    again = raw_input("Enter 'y' to run another, enter 'n' to exit: ")

print("Have a nice day :) ")

希望这有帮助！

使用它代替python 3：

print("Do you want to find the area of a circle?")
again = input("Enter 'y' for yes, or enter 'n' to exit the program: ")

while (again == 'y'):

    pi = 3.14

    radius = input("Input the radius of the circle: ")
    area = pi * (float(radius) ** 2)

    print("A circle with a radius of " + str(radius) + " has an area of " + "{0:.2f}".format(area))

    print("Would you like to run another?")
    again = input("Enter 'y' to run another, enter 'n' to exit: ")

print("Have a nice day :)")

我如何根据Python中的输入输出整数和浮点数？

2 个答案: