如何使用 requirements.txt 在 python 项目中安装所有依赖项

Question

我是 python 的新手。最近我得到了一个 python 写的项目，它需要一些安装。我运行下面的命令进行安装但出现错误。

# pip install requirements.txt 
Collecting requirements.txt
  Could not find a version that satisfies the requirement requirements.txt (from versions: )
No matching distribution found for requirements.txt

我在 google 上搜索并找到了这个 link 但我不太明白 post.

 中的解决方案

下面是我的 requirements.txt 文件：

# cat requirements.txt 
ordereddict==1.1
argparse==1.2.1
python-dateutil==2.2
matplotlib==1.3.1
nose==1.3.0
numpy==1.8.0
pymongo==3.3.0
psutil>=2.0


是否有一种简单的方法可以在此 python 项目中安装所有必需的依赖项？ 

EDIT1

下面是 pip3 install -r requirements.txt. 的输出

# pip3 install -r requirements.txt 
Requirement already satisfied: ordereddict==1.1 in /usr/local/lib/python3.5/dist-packages (from -r requirements.txt (line 1))
Collecting argparse==1.2.1 (from -r requirements.txt (line 2))
  Using cached argparse-1.2.1.tar.gz
Collecting python-dateutil==2.2 (from -r requirements.txt (line 3))
  Using cached python-dateutil-2.2.tar.gz
Collecting matplotlib==1.3.1 (from -r requirements.txt (line 4))
  Using cached matplotlib-1.3.1.tar.gz
    Complete output from command python setup.py egg_info:
    ============================================================================
    Edit setup.cfg to change the build options

    BUILDING MATPLOTLIB
                matplotlib: yes [1.3.1]
                    python: yes [3.5.2 (default, Nov 17 2016, 17:05:23)  [GCC
                            5.4.0 20160609]]
                  platform: yes [linux]

    REQUIRED DEPENDENCIES AND EXTENSIONS
                     numpy: yes [version 1.11.3]
                  dateutil: yes [using dateutil version 2.6.0]
                   tornado: yes [tornado was not found. It is required for the
                            WebAgg backend. pip/easy_install may attempt to
                            install it after matplotlib.]
                 pyparsing: yes [using pyparsing version 2.1.10]
                     pycxx: yes [Official versions of PyCXX are not compatible
                            with Python 3.x.  Using local copy]
                    libagg: yes [pkg-config information for 'libagg' could not
                            be found. Using local copy.]
                  freetype: no  [The C/C++ header for freetype2 (ft2build.h)
                            could not be found.  You may need to install the
                            development package.]
                       png: yes [pkg-config information for 'libpng' could not
                            be found. Using unknown version.]

    OPTIONAL SUBPACKAGES
               sample_data: yes [installing]
                  toolkits: yes [installing]
                     tests: yes [using nose version 1.3.7]

    OPTIONAL BACKEND EXTENSIONS
                    macosx: no  [Mac OS-X only]
                    qt4agg: no  [PyQt4 not found]
                   gtk3agg: no  [gtk3agg backend does not work on Python 3]
                 gtk3cairo: no  [Requires cairo to be installed.]
                    gtkagg: no  [Requires pygtk]
                     tkagg: no  [TKAgg requires Tkinter.]
                     wxagg: no  [requires wxPython]
                       gtk: no  [Requires pygtk]
                       agg: yes [installing]
                     cairo: no  [cairo not found]
                 windowing: no  [Microsoft Windows only]

    OPTIONAL LATEX DEPENDENCIES
                    dvipng: no
               ghostscript: no
                     latex: no
                   pdftops: no

    ============================================================================
                            * The following required packages can not be built:
                            * freetype

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-don4ne_2/matplotlib/


我已经安装了 libfreetype6-dev 但 pip 命令仍然报告缺少此依赖项。

# apt-get install libfreetype6-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libfreetype6-dev is already the newest version (2.6.1-0.1ubuntu2).
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.

Answer 1

pip install -r requirements.txt 对于 python 2.x

pip3 install -r requirements.txt for python 3.x（如果安装了多个版本）

Answer 2

（摘自我的评论）

pip 不会处理系统级依赖项。在继续之前，您必须 apt-get install libfreetype6-dev。（它甚至在你的输出中这么说。下次尝试浏览它以查找此类错误，通常构建输出非常详细）

Answer 3

如果您正在使用 Linux OS:

从 requirements.txt

matplotlib==1.3.1

尝试使用 sudo apt-get install python-matplotlib
运行 pip install -r requirements.txt (Python 2), 或 pip3 install -r requirements.txt (Python 3)
pip freeze > requirements.txt

如果您正在使用 Windows OS:

python -m pip install -U pip setuptools
python -m pip install matplotlib

Answer 4

python -m pip install -r requirements.txt

参考：How to install packages using pip according to the requirements.txt file from a local directory?

Answer 5

Python 3:

pip3 install -r requirements.txt

Python 2:

pip install -r requirements.txt

获取虚拟环境或整个系统的所有依赖项：

pip freeze

将所有依赖推送到requirements.txt (Linux):

pip freeze > requirements.txt

Answer 6

如果您想在需求文件中安装所有依赖项，例如 npm install 在 Node.js 项目上

在python你运行以下命令：

pip3 install -r  ./requirements.txt

您可以使用 pip 或 pip3 两者都有效

Answer 7

如果您使用 Linux 作为 OS，那么您可以按照以下步骤操作：-

首先，从 requirements.txt

中删除 matplotlib==1.3.1

之后尝试使用

安装它

sudo apt-get install python-matplotlib

运行 pip install -r requirements.txt (Python 2)
或 pip3 install -r requirements.txt (Python 3)

pip freeze > requirements.txt

如果您使用 Windows 作为 OS，请执行以下步骤：

python -m pip install -U pip setuptools

python -m pip install matplotlib

看看这个 install all dependencies in a python project page.

如何使用 requirements.txt 在 python 项目中安装所有依赖项

How to use requirements.txt to install all dependencies in a python project

python

pip

requirements.txt