python中的變量定義是很靈活的，很容易搞混淆，特別是對于class的變量的定義，如何定義使用類里的變量是我們維護代碼和保證代碼穩定性的關鍵。

#!/usr/bin/python

#encoding:utf-8

global_variable_1 = 'global_variable'

class MyClass():

class_var_1 = 'class_val_1' # define class variable here

def __init__(self, param):

self.object_var_1 = param # define object variable here

self.object_var_2 = 'object_val_2' # define object variable here

self.object_func3()

def object_func1(self, param):

local_var_1 = param # define lcoal variable here

local_var_2 = 'local_val_2' # define local variable here

self.internal_var_1 = 'internal_val_1' # define internal variable here

print(local_var_1) # we can use local variable of current here

print(local_var_2) # we can use local variable of current here

print(MyClass.class_var_1) # we can use class variable here, but you have using class name ass prefix

print(self.class_var_1) # we can use class variable as object variable here

print(self.object_var_1) # we can use object variable here

print(self.object_var_2) # we can use object variable here

print(self.internal_var_1) # we can use internal variable here

#print(local_var_3) # we can't use local variable in another function

print(global_variable_1) # we can use global variable here

def object_func2(self, param='func_val_1'):

local_var_3 = param # define local variable here

print(local_var_3) # we can use lcoal variable here

print(self.internal_var_1) # we can use internal variable defined in class_func1, but you have to call class_func1 first

print(MyClass.class_var_1) # we can use class variable here, but you have using class name ass prefix

print(self.class_var_1) # we can class variable here

print(self.object_var_1) # we can use object variable here

print(self.object_var_2) # we can use object variable here

print(global_variable_1) # we can use global variable here

def object_func3(self, param='func_val_1'):

self.object_var_3 = param # because this function called in construction function, so this is defined as object variable, not internal variable

self.object_var_4 = 'object_val_4' # because this function called in construction function, so this is defined as object variable, not internal variable

print(global_variable_1) # we can use global variable here

# define class function

def class_func4():

print(MyClass.class_var_1)

print(global_variable_1) # we can use global variable here

if __name__ == '__main__':

myObject = MyClass('object_val_1')

print(MyClass.class_var_1) # we can use class variable directly here

#print(MyClass.object_var_1) # we can't use object variable here

print(myObject.object_var_1) # we can use object variable here

print(myObject.object_var_2) # we can use object variable here

print(myObject.object_var_3) # we can use object variable here

print(myObject.object_var_4) # we can use object variable here

#print(myObject.internal_var_1) # we can't use internal variable as object variable here

MyClass.class_func4() # we can use class function here

#MyClass.object_func2(myObject, 'local_var_3') # internal variable can't be used in this function

myObject.object_func1('local_var_1') # call first function

myObject.object_func2('local_var_3') # call second function

print(global_variable_1) # we can use global variable here

簡單的寫了個測試小程序，枚舉了各種情況，沒有辦法全部枚舉，但大部分情況應該都已經包含了。

1. 類變量：能夠通過類名或者object的self來訪問到，在類的內部和外部均可達，比如class_var_1

2. 對象變量：可以通過對象的self來使用的變量，通過constructor一路走向去的的self初次被賦值的變量都會成為對象變量，比如object_var_1, object_var_2, object_var_3, object_var_4

3. 內部變量：可以在函數中定義，并加上self前綴，在初次調用過定義的函數后，就可以在后面的對象的函數中被使用，比如internal_var_1

4. 局部變量：在函數內部定義，并使用的變量，在使用完之后就會被回收對類及object不可見

5. 全局變量：定義在類或者函數外部，作用域在變量被定義之后的任意代碼段，比如：global_var_1

以上是基于我自己的測試得到的結論，如果有不對的地方，可以幫忙指正。

這篇對python 中class與變量的使用方法詳解就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持我們。

本文標題: 對python 中class與變量的使用方法詳解

本文地址: http://www.cppcns.com/jiaoben/python/263751.html

總結

以上是生活随笔為你收集整理的python中class变量_对python 中class与变量的使用方法详解的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。