Python's Way of learning Int () Strange error

Today I have nothing to look at Python basics, when learning the Int () method for data type conversions. Found such an interesting thing, the IDE or the interpreter is a small bug. (The specific reason is unknown, left to find the problem later)

Let's talk about the environment.

• Operating system: WINDOWS10
• Python version: 3.6.5
• IDE environment: Pycharm edu 2018.1 x64
• Interpreter: CPython

then the int () method acts

Function	Description
Int (X[,base])	J converts x to an integer

Gossip less about the code:

Scenario 1:

# -*-coding:utf-8-*->>>age=input ()>>>print(int (age))15

Output normal

Scenario 2:

# -*-coding:utf-8-*->>>print(int (15.6))                  # when using int () conversion, Forces the number after the decimal point to be omitted

Output normal

Scenario 3:

# -*-coding:utf-8-*-age = input (" Please enter ages:")if int >=18 :     Print (" congratulations on your manhood ") Else :     Print (" you still need to grow ")

If the user enters a normal integer string without a decimal point, there is no problem with the conversion output.

When the user enters a floating-point string, a strange error occurs when the data type conversion begins:

#-*-coding:utf-8-*-Age = Input ("Please enter your age:")ifInt (age) >=18: #这里的age是字符串类型, but is treated as a number in a conditional expression Print("Congratulations on your manhood.")Else:    Print("you still need to grow")#after executing the above parameters, enter the value 15.6, the following error (not only the input string with a decimal point, as long as the non-integer characters, will be an error)Traceback (most recent): File ' c:/pythonstudy/startpython/day1.py ', line 6, ' in <module> if int ' (age ) >=18 :valueerror:invalid literal for Int () with base: ' 15.6 ' #值错误: Int () invalid text with base 10: ' 15.6 ' 

However, there is no problem in the case of 1 when entering a decimal number for conversion. What is the problem?

Find a solution through Baidu

##-*-Coding:utf-8-*-Import re #引入正则模块Age = Input ("Please enter your age:") TotalCount= Re.sub ("\d","", age) #使用正则的sub方法过滤掉输入的字符串中age带的非数字字符和空的值. ifInt (totalcount) >=18:    Print("Congratulations on your manhood.")Else:    Print("you still need to grow")

When you enter a string with a decimal point, no more error errors will occur. (But the random input of non-digital symbols will be an error). But printing totalconunt, you will find that this method not only removes the string age with non-numeric characters and null values, even the decimal point is removed.

But with the following code:

# -*-coding:utf-8-*-age = Int (float (input (" Please enter ages:")))if int ( Age) >=18:    print(" congratulations on your manhood ")Else  :    print(" you still need to grow ")

You will find that you can enter a decimal point again. It's not going to be an error.

Initially, the Int () function converts the string of a pure integer number, without a decimal point, to an error. Int (the method should be that the decimal point does not belong to a pure integer category). Float () can convert a pure integer numeric string or a pure floating-point string with a decimal point.

Python's Way of learning Int () Strange error