How to judge whether the input content is "number"

When you want users to enter a number , Will use input function , however input The function does not restrict what the user enters , Users can also enter string or other format content .

Run the following code ：

When the user enters the correct number , Output is as follows ：

When user input error , Output is as follows

If you want users to input numbers as required, you need to judge the user's input content and then output .

Because the string content cannot be converted to floating point （float）, You can convert user input to floating point （float） As the result of the True still False To judge .

Run the following code

If the input is not a number , Output is as follows ：