python中 import 和from import 的区别 python import 和 from XX import...
Python\u7684from import\u548cimport\u7684\u533a\u522b\u4e00\u3001import\u548cfrom import\u7684\u533a\u522b:
import \u53ea\u80fd\u5bfc\u5165\u6a21\u5757\u3001\u5b50\u5305\u3001\u5305, \u800c\u4e0d\u80fd\u5bfc\u5165\u6a21\u5757\u4e2d\u7684\u7c7b\u3001\u51fd\u6570\u3001\u53d8\u91cf\u7b49
from import \u53ef\u4ee5\u5bfc\u5165\u6a21\u5757\u3001\u5b50\u5305\u3001\u5305\u3001\u7c7b\u3001\u51fd\u6570\u3001\u53d8\u91cf\u4ee5\u53ca\u5728\u5305\u7684__init__.py\u4e2d\u5df2\u7ecf\u5bfc\u5165\u7684\u540d\u5b57
ps: \u4f46\u662f\u4e24\u8005\u90fd\u53ef\u4ee5\u7528as\u7ed9\u5bfc\u5165\u7684\u540d\u5b57\u91cd\u547d\u540d
\u4e8c\u3001\u5305\u5bfc\u5165\u7684\u6ce8\u610f\u4e8b\u9879
\u4e0d\u80fd\u5728\u5bfc\u5165\u7684\u8def\u5f84\u4e2d\u4f7f\u7528\u5df2\u7ecf\u5bfc\u5165\u8fc7\u7684\u540d\u5b57, \u6bd4\u5982 import numpy as np; import np.random as rn, \u8fd9\u4f1a\u62a5\u9519, \u8bf4\u6ca1\u6709\u627e\u5230\u540d\u5b57\u53ebnp\u7684model, \u8fd9\u5176\u5b9e\u5c31\u8bf4\u660epython\u5bfb\u627e\u5305\u8def\u5f84\u7684\u65f6\u5019, \u662f\u5728\u6587\u4ef6\u7cfb\u7edf\u4e2d\u5bfb\u627e, \u800c\u4e0d\u5305\u542b\u5f53\u524d\u547d\u540d\u7a7a\u95f4\u4e2d\u7684\u540d\u5b57, \u5373\u4e0e\u5f53\u524d\u7684\u7a0b\u5e8f\u6267\u884c\u73af\u5883\u6ca1\u6709\u5173\u7cfb\u7684
\u5bfc\u5165\u4e00\u4e2a\u5305\u65f6, \u5219\u8fd9\u4e2a\u5305\u53ef\u7528\u7684\u5c5e\u6027\u90fd\u5fc5\u987b\u5728__init__.py\u6587\u4ef6\u4e2d\u5b9a\u4e49, \u8fd9\u5c31\u662f\u8bf4\u5982\u679c\u4e00\u4e2a\u5305\u7684__init__.py\u6587\u4ef6\u662f\u7a7a\u7684, \u5219\u5373\u4f7f\u5305\u91cc\u8fb9\u6709\u51e0\u4e2a\u6a21\u5757\u6587\u4ef6, \u4e5f\u65e0\u6cd5\u901a\u8fc7\u8fd9\u4e2a\u5305\u540d\u53bb\u4f7f\u7528, \u6bd4\u5982pkg\u4e0b\u6709a.py\u548cb.py\u4e24\u4e2a\u6587\u4ef6, \u4f46\u662f__init__.py\u4e2d\u6ca1\u6709\u5bfc\u5165\u6a21\u5757a\u548cb,\u5219import pkg as pg \u540e, \u65e0\u6cd5\u4f7f\u7528pg.a\u548cpg.b,\u8fd9\u4e2a\u8bf4\u660e\u5305\u5185\u7684\u6a21\u5757\u548c\u5b50\u5305\u4e0d\u4f1a\u81ea\u52a8\u52a0\u5165\u5230\u5305\u7684\u540d\u5b57\u7a7a\u95f4\u91cc\u8fb9, \u9700\u8981\u624b\u52a8\u901a\u8fc7__init__.py\u6307\u5b9a\u540e\u624d\u4f1a\u52a0\u5165\u3002\u8fd9\u4e00\u70b9\u4e0a\u6a21\u5757\u548c\u5305\u4e0d\u592a\u4e00\u6837, \u6a21\u5757\u4e2d\u7684\u7b26\u53f7\u662f\u81ea\u52a8\u5bfc\u5165\u7684\uff0c\u56e0\u6b64\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7\u6a21\u5757\u540d\u6765\u8c03\u7528
\u7b2c2\u70b9\u53ea\u662f\u8bf4\u65e0\u6cd5\u901a\u8fc7pg\u8fd9\u4e2a\u540d\u5b57\u6765\u4f7f\u7528\u6a21\u5757a\u548cb, \u4f46\u662f\u6211\u4eec\u53ef\u4ee5\u624b\u52a8\u5bfc\u5165a\u548cb\u7684, \u7528import pkg.a as a\u548cfrom pkgs import a as a\u90fd\u662f\u53ef\u4ee5\u7684
\u5bfc\u5165\u4e00\u4e2a\u957f\u4e32\u7684\u8def\u5f84\u65f6, \u5219\u8fd9\u4e2a\u8def\u5f84\u4e0a\u7684\u6240\u6709\u5305\u7684__init__.py\u90fd\u4f1a\u88ab\u6267\u884c, \u5e76\u4e14\u5305\u7684\u5bf9\u5e94\u5b50\u5305\u4e5f\u4f1a\u88ab\u52a0\u5165\u5230\u5305\u7684\u5c5e\u6027\u4e2d\u53bb, \u6bd4\u5982\u6211\u4eec\u73b0\u5728\u6709\u8fd9\u6837\u4e00\u4e2a\u5305\u7ed3\u6784: pkgs\u4e0b\u6709\u4e24\u4e2a\u5b50\u5305pkga\u548cpkgb, \u4e14pkgs/init.py\u662f\u7a7a\u6587\u4ef6,\u5219import pkgs\u8bed\u53e5\u662f\u65e0\u6cd5\u4f7f\u7528pkgs.pkga\u8fd9\u6837\u7684\u53e5\u5b50\u7684, \u4f46\u662f\u5982\u679c\u6211\u4eec\u540e\u7eed\u53c8\u4f7f\u7528\u4e86\u4e00\u4e2aimport\u8bed\u53e5: import pkgs.pkga.a as a,\u5219\u6b64\u65f6pkgs\u7684\u540d\u5b57\u7a7a\u95f4\u91cc\u4f1a\u52a0\u5165pkga\u8fd9\u4e2a\u5c5e\u6027,\u4e5f\u5c31\u662f\u53ef\u4ee5\u4f7f\u7528pkgs.pkga\u4e86
ps: from pkgs.pkga.a import fun_a\u8fd9\u79cd\u957f\u8def\u5f84\u5f62\u5f0f, \u867d\u7136\u4f1a\u6267\u884cpkgs\u548cpkga\u7684__init__.py\u4ee5\u53ca\u6a21\u5757a\u7684\u4ee3\u7801,
\u4e00\u3001\u4f5c\u7528\u4e0d\u540c
1\u3001import\uff1a \u53ef\u4ee5\u4fee\u6539\u6a21\u5757\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u65e0\u8bba\u5c5e\u6027\u662f\u4e0d\u662f\u53ef\u53d8\u7c7b\u578b\u3002
2\u3001 from XX import * \uff1a\u53ea\u80fd\u4fee\u6539\u6a21\u5757\u5bf9\u8c61\u7684\u5c5e\u6027\u662f\u53ef\u53d8\u7c7b\u578b\u7684\uff0c\u4e0d\u53ef\u53d8\u7c7b\u578b\u4e0d\u80fd\u4fee\u6539\u3002
\u4e8c\u3001\u7528\u6cd5\u4e0d\u540c
1\u3001import\uff1aimport xx\uff0c\u4ee5import time\u548c\u521b\u5efa\u7684\u4e00\u4e2apython\u7c7b\u4e3a\u4f8b\uff1a\u8c03\u7528time\u6a21\u5757\u4e2d\u7684\u65b9\u6cd5\u65f6\uff0c\u9700\u8981\u5728\u524d\u52a0\u4e0atime.\uff1b\u800c\u8c03\u7528\u7c7b\u4e2d\u7684\u65b9\u6cd5\u65f6\uff0c\u4e5f\u9700\u8981\u5728\u524d\u9762\u52a0\u4e0a\u5b9e\u4f8b\u540daa\u3002
2\u3001 from XX import * \uff1a\u4f7f\u7528\u8fd9\u79cd\u65b9\u5f0f\uff0c\u5219\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\u3002
\u4e09\u3001\u7279\u70b9\u4e0d\u540c
1\u3001import\uff1a\u6240\u6709\u5bfc\u5165\u7684\u7c7b\u4f7f\u7528\u65f6\u9700\u52a0\u4e0a\u6a21\u5757\u540d\u7684\u9650\u5b9a\u3002
2\u3001 from XX import * \uff1a\u6240\u6709\u5bfc\u5165\u7684\u7c7b\u4e0d\u9700\u8981\u6dfb\u52a0\u9650\u5b9a\u3002
\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a\u767e\u5ea6\u767e\u79d1-Import
\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a\u767e\u5ea6\u767e\u79d1-Python
from [package/module] import [module/class]从一个包/模块导入一个模块/类
扩展阅读：python import用法 ... python importerror ... for i in range ... from random import ... from math import ... import math as m ... python import random ... 代码import什么意思 ... python random ...
