如果我运行,从干净的 python 2.7.3 安装开始
pip install -r requirements.txt
具有以下 requirements.txt:
Flask==0.10.1
Flask-Cache==0.12
Jinja2==2.7.1
MarkupSafe==0.18
Werkzeug==0.9.4
gunicorn==18.0
itsdangerous==0.23
wsgiref==0.1.2
numpy==1.7.1
PIL==1.1.7
matplotlib==1.2.1
然后 pip 尝试在 numpy 之前安装 matplotlib 并失败:
============================================================================
BUILDING MATPLOTLIB
matplotlib: 1.2.1
python: 2.7.3 (default, Jan 2 2013, 13:56:14) [GCC 4.7.2]
platform: linux2
REQUIRED DEPENDENCIES
numpy: no
* You must install numpy 1.4 or later to build
* matplotlib.
Complete output from command python setup.py egg_info:
basedirlist is: ['/usr/local', '/usr']
============================================================================
但是,如果我这样做
pip install numpy
pip install -r requirements.txt
然后一切正常。这里发生了什么?