終端輸入命令：pip install requests

如果報錯：

Installing collected packages: idna, urllib3, certifi, chardet, requests

Exception:

Traceback (most recent call last):

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/basecommand.py", line 215, in main

status = self.run(options, args)

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/commands/install.py", line 342, in run

prefix=options.prefix_path,

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_set.py", line 784, in install

**kwargs

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_install.py", line 851, in install

self.move_wheel_files(self.source_dir, root=root, prefix=prefix)

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_install.py", line 1064, in move_wheel_files

isolated=self.isolated,

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/wheel.py", line 345, in move_wheel_files

clobber(source, lib_dir, True)

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/wheel.py", line 316, in clobber

ensure_dir(destdir)

File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/utils/__init__.py", line 83, in ensure_dir

os.makedirs(path)

File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.py", line 157, in makedirs

mkdir(name, mode)

OSError: [Errno 13] Permission denied: ‘/Library/Python/2.7/site-packages/idna‘

解決方案：

當前路徑/Library/Python/2.7 沒有權限

在終端中輸入命令：sudo chown -R $USER /Library/Python/2.7

python教程：http://www.runoob.com/python3/python3-errors-execptions.html

python學習之爬蟲：安裝requests模塊