Step by step, learn python (6)-Abstraction

1. Convert string to numeric

Import locale

Locale. atoi (str)

2. Create a function

A function can be called (may contain parameters) to execute a behavior and return a value.

>>> Import math

>>> X = 1

>>> Y = math. sqrt

>>> Cllable (x)

False

>>> Callable (y)

True

Define a function using def

Def hello (name ):

Return 'hello, '+ name + '! '

In this way, a hello function is defined.

3. Record Functions

Def square (x)

'Calculates the square of the number x .'

Return x * x

The document can be accessed as follows

Square. _ doc _

'Calculates the square of the number x .'

The built-in function help is very useful. You can obtain the function information in the interactive interpreter.

Help (square)

4. Keyword parameters and default values,

5. Collect Parameters

Def print (* param)

* Before the parameter, place all values in a single tuple.

6. Reversal Process

7. Scope

In addition to the global scope, each function creates a scope.

8. Recursion

Function calls are called recursion.