当我在python 2.7的brew安装版本上使用pip freeze时，我得到一个导入错误，没有名为zlib的模块。
➜ ~ pip freeze
Traceback (most recent call last):
File "/usr/local/bin/pip", line 9, in <module>
load_entry_point('pip==7.1.2', 'console_scripts', 'pip')()
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 558, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2682, in load_entry_point
return ep.load()
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2355, in load
return self.resolve()
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2361, in resolve
module = __import__(self.module_name, fromlist=['__name__'], level=0)
File "/usr/local/lib/python2.7/site-packages/pip/__init__.py", line 15, in <module>
from pip.vcs import git, mercurial, subversion, bazaar # noqa
File "/usr/local/lib/python2.7/site-packages/pip/vcs/mercurial.py", line 10, in <module>
from pip.download import path_to_url
File "/usr/local/lib/python2.7/site-packages/pip/download.py", line 38, in <module>
from pip._vendor import requests, six
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/__init__.py", line 58, in <module>
from . import utils
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/utils.py", line 26, in <module>
from .compat import parse_http_list as _parse_list_header
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/compat.py", line 7, in <module>
from .packages import chardet
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/__init__.py", line 3, in <module>
from . import urllib3
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/__init__.py", line 10, in <module>
from .connectionpool import (
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/connectionpool.py", line 38, in <module>
from .response import HTTPResponse
File "/usr/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/response.py", line 5, in <module>
import zlib
ImportError: No module named lib
我认为这通常是用python安装的，但我已经用brew安装了python(2.7)，卸载并重新安装brew不能解决这个问题?
➜ ~ which pip
/usr/local/bin/pip
➜ ~ which python
/usr/local/bin/python
对于安装了Xcode-beta的macOs 10.14 mojave用户，以下内容应该可以工作，因为xcode-select --install似乎不提供缺失的头文件，至少不在通过brew安装python的位置…
对我有效的方法如下:
brew install zlib
brew link zlib --force
#python 3
brew (re)install python3
brew postinstall python3
brew link python3 #just in case...
#python 2
brew (re)install python2
brew link python2 #just in case...
在我的情况下，我还必须重新安装一些以前通过pip安装的python模块。
这是xcode没有正确安装zlib的问题。
安装xcode CLI:
xcode-select --install
然后在用brew重新安装Python之前，我检查zlib头是否在brew通过终端查找它的地方:
ls /usr/include/zlib.h
然后重新安装python:
brew reinstall python
对于我来说，上述方法都不起作用，我不得不将zlib.h头文件直接链接到/usr/
brew install zlib
ln -s /usr/local/Cellar/zlib/1.2.11/include/zlib.h /usr/local/include/zlib.h
之后，当我尝试pip install Pillow==2.2.2(我在一个老项目上工作)…我终于得到了想要的"ZLIB (PNG/ZIP)支持可用"输出
PIL SETUP SUMMARY
--------------------------------------------------------------------
version Pillow 2.2.2
platform darwin 3.5.8 (default, Dec 4 2019, 15:51:38)
[GCC 4.2.1 Compatible Apple LLVM 11.0.0 (clang-1100.0.33.12)]
--------------------------------------------------------------------
...
--- ZLIB (PNG/ZIP) support available
对于那些无法使用上述解决方案的人，请使用homebrew的建议。
export LDFLAGS="-L/usr/local/opt/zlib/lib"
export CPPFLAGS="-I/usr/local/opt/zlib/include"
以下内容对我毫无帮助:
xcode-select --install
或
brew link zlib --force
相反，它给了我一个错误消息:
Warning: Refusing to link macOS-provided software: zlib
For compilers to find zlib you may need to set:
export LDFLAGS="-L/usr/local/opt/zlib/lib"
export CPPFLAGS="-I/usr/local/opt/zlib/include"
For pkg-config to find zlib you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/zlib/lib/pkgconfig"