我尝试在https://github.com/dennybritz/rnn-tutorial-rnnlm上做教程。当我做pip install -r requirements.txt时，我收到了如下错误消息：
(venv) ~/PycharmProjects/rnn-tutorial-rnnlm $ pip install -r requirements.txt
Collecting appnope==0.1.0 (from -r requirements.txt (line 1))
Using cached appnope-0.1.0-py2.py3-none-any.whl
Collecting backports.ssl-match-hostname==3.4.0.2 (from -r requirements.txt (line 2))
Using cached backports.ssl_match_hostname-3.4.0.2.tar.gz
Collecting certifi==2015.9.6.2 (from -r requirements.txt (line 3))
Using cached certifi-2015.9.6.2-py2.py3-none-any.whl
Collecting decorator==4.0.2 (from -r requirements.txt (line 4))
Using cached decorator-4.0.2-py2.py3-none-any.whl
Collecting funcsigs==0.4 (from -r requirements.txt (line 5))
Using cached funcsigs-0.4-py2.py3-none-any.whl
Collecting functools32==3.2.3.post2 (from -r requirements.txt (line 6))
Using cached functools32-3.2.3-2.zip
Collecting gnureadline==6.3.3 (from -r requirements.txt (line 7))
Using cached gnureadline-6.3.3.tar.gz
Collecting ipykernel==4.0.3 (from -r requirements.txt (line 8))
Using cached ipykernel-4.0.3-py2.py3-none-any.whl
Collecting ipython==4.0.0 (from -r requirements.txt (line 9))
Using cached ipython-4.0.0-py2-none-any.whl
Collecting ipython-genutils==0.1.0 (from -r requirements.txt (line 10))
Using cached ipython_genutils-0.1.0-py2.py3-none-any.whl
Collecting ipywidgets==4.0.2 (from -r requirements.txt (line 11))
Using cached ipywidgets-4.0.2-py2.py3-none-any.whl
Collecting Jinja2==2.8 (from -r requirements.txt (line 12))
Using cached Jinja2-2.8-py2.py3-none-any.whl
Collecting jsonschema==2.5.1 (from -r requirements.txt (line 13))
Using cached jsonschema-2.5.1-py2.py3-none-any.whl
Collecting jupyter==1.0.0 (from -r requirements.txt (line 14))
Using cached jupyter-1.0.0-py2.py3-none-any.whl
Collecting jupyter-client==4.0.0 (from -r requirements.txt (line 15))
Using cached jupyter_client-4.0.0-py2.py3-none-any.whl
Collecting jupyter-console==4.0.2 (from -r requirements.txt (line 16))
Using cached jupyter_console-4.0.2-py2.py3-none-any.whl
Collecting jupyter-core==4.0.6 (from -r requirements.txt (line 17))
Using cached jupyter_core-4.0.6-py2.py3-none-any.whl
Collecting MarkupSafe==0.23 (from -r requirements.txt (line 18))
Using cached MarkupSafe-0.23.tar.gz
Collecting matplotlib==1.4.3 (from -r requirements.txt (line 19))
Using cached matplotlib-1.4.3.tar.gz
Complete output from command python setup.py egg_info:
============================================================================
Edit setup.cfg to change the build options
BUILDING MATPLOTLIB
matplotlib: yes [1.4.3]
python: yes [2.7.12 (default, Nov 19 2016, 06:48:10) [GCC
5.4.0 20160609]]
platform: yes [linux2]
REQUIRED DEPENDENCIES AND EXTENSIONS
numpy: yes [version 1.12.1]
six: yes [using six version 1.10.0]
dateutil: yes [dateutil was not found. It is required for date
axis support. pip/easy_install may attempt to
install it after matplotlib.]
pytz: yes [pytz was not found. pip will attempt to install
it after matplotlib.]
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 2.2.0]
pycxx: yes [Couldn't import. 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: no [The C/C++ header for libpng (png.h) could not
be found. You may need to install the development
package.]
qhull: yes [pkg-config information for 'qhull' could not be
found. Using local copy.]
OPTIONAL SUBPACKAGES
sample_data: yes [installing]
toolkits: yes [installing]
tests: yes [nose 0.11.1 or later is required to run the
matplotlib test suite. pip/easy_install may attempt
to install it after matplotlib. / mock is required
to run the matplotlib test suite. pip/easy_install
may attempt to install it after matplotlib.]
toolkits_tests: yes [nose 0.11.1 or later is required to run the
matplotlib test suite. pip/easy_install may attempt
to install it after matplotlib. / mock is required
to run the matplotlib test suite. pip/easy_install
may attempt to install it after matplotlib.]
OPTIONAL BACKEND EXTENSIONS
macosx: no [Mac OS-X only]
qt5agg: no [PyQt5 not found]
qt4agg: no [PyQt4 not found]
pyside: no [PySide not found]
gtk3agg: no [Requires pygobject to be installed.]
gtk3cairo: no [Requires cairocffi or pycairo 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 [cairocffi or pycairo not found]
windowing: no [Microsoft Windows only]
OPTIONAL LATEX DEPENDENCIES
dvipng: no
ghostscript: yes [version 9.18]
latex: no
pdftops: yes [version 0.41.0]
============================================================================
* The following required packages can not be built:
* freetype, png
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-SBYScG/matplotlib/
为什么会发生这些事情？任何帮助将非常感谢！提前谢谢你！
答案 0 :(得分：0)
freetype: no [The C/C++ header for freetype2 (ft2build.h) could not be found. You may need to install the development package.]
png: no [The C/C++ header for libpng (png.h) could not be found. You may need to install the development package.]
这清楚地表明你必须安装freetype2和libpng头文件。