Differences

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--- python3 [2017/02/01 16:23] – dblume
+++ python3 [2023/04/14 20:37] (current) – dblume
@@ Line 1: / Line 1: @@
 ====== Python3 ======
-If I want Python 3.6, I have to compile it myself.  Use "dnf" for RedHat based distros and "apt-get" for Debian.
+If I want Python 3.7, I have to compile it myself.  Use "dnf" for RedHat based distros and "apt-get" for Debian.
+===== RedHat based distros =====
 <code bash>
@@ Line 9: / Line 11: @@
 </code>
-I haven't tested [[http://www.unixmen.com/howto-install-python-3-x-in-ubuntu-debian-fedora-centos/|the following]]:
+Then on Fedora and CentOS...
 <code bash>
-sudo apt-get install build-essential libncursesw5-dev libreadline5-dev libssl-dev libgdbm-dev libc6-dev libsqlite3-dev tk-dev
+wget https://www.python.org/ftp/python/3.7.0/Python-3.7.0.tgz
+tar -xvf Python-3.7.0.tgz
+cd Python-3.7.0/
+./configure --prefix=/usr/local/bin/python3.7 --enable-optimizations
+make
+sudo make install
+# sudo ln -s /usr/local/bin/python3.7/bin/python3 /usr/bin/python3
 </code>
-Then...
+On my dev system at work, I seem to have configured a prefix like /opt/python3. Then when CentOS updates itself, it changes a symbolic link in /usr/bin/python3
+    sudo rm /usr/bin/python3 && sudo ln -s /opt/python3/bin/python3 /usr/bin/python3
+For **OS X**, brew upgrading httpie seems to upgrade to the latest Python 3, so I didn't have to do stuff.
+===== Debian based distros (Start) =====
+For Debian (eg., Rasbian) try [[http://www.unixmen.com/howto-install-python-3-x-in-ubuntu-debian-fedora-centos/|the following]] (on raspberry pi libssl-dev isn't available):
 <code bash>
-wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tgz
+sudo apt-get install build-essential libncursesw5-dev libreadline-dev libssl-dev libgdbm-dev libc6-dev libsqlite3-dev tk-dev libffi-dev
-tar -xvf Python-3.6.0.tgz
+</code>
-cd Python-3.6.0/
-./configure --prefix=/opt/python3
+==== (Aside) OpenSSL 1.0.1 issue in Raspbian ====
+On Raspbian Jessie the make command (below) may have output that looks like this:
+<code>
+The necessary bits to build these optional modules were not found:
+_bz2                  _lzma                 _ssl
+</code>
+On Raspbian, the pip module may not work because it relies on the ssl module.
+<code>
+pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
+</code>
+Python's setup.py explains:
+> Python requires an OpenSSL 1.0.2 or 1.1 compatible libssl with X509_VERIFY_PARAM_set1_host().
+If you check the version of ssh:
+<code>
+$ openssl version
+OpenSSL 1.0.1t  3 May 2016
+</code>
+That OpenSSL is too old. So you may have to [[https://raspberrypi.stackexchange.com/questions/66782/how-to-install-openssl-1-0-2-on-raspberry-pi3/67045|make your own OpenSSL library]].
+<code bash>
+# Add the backport apt source.
+echo "deb-src http://httpredir.debian.org/debian jessie-backports main contrib non-free" | \
+      sudo tee /etc/apt/sources.list.d/jessie-backports.list
+sudo apt update
+# Get the openssl source
+apt-get source openssl/jessie-backports
+# Make and install it.
+cd openssl-1.0.2k/
+./config --prefix=/usr
 make
+make test
 sudo make install
-# sudo ln -s /opt/python3/bin/python3 /usr/bin/python3
+</code>
+**Update**: The following apt-cache policy command showed the old libssl was still installed. It's probably bad, but I [[https://my-take-on.tk/2018/09/10/installing-latest-python-3x-and-pip-on-any-debian-based-system/|installed the new one with apt install -t jessie-backports]].
+<code>
+sudo apt-cache policy libssl-dev
+</code>
+===== Debian based distros (Continued) =====
+Then, back to Python3, on Raspbian, I put it in the default location, /usr/local:
+<code bash>
+screen  # Because using optimizations will take hours
+cd Python-3.7.0/
+./configure --enable-optimizations
+make -j4
+sudo make install
+[[ $TERM != "screen" ]] || exit  # exit if in screen session
+</code>
+===== Modules =====
+Sometimes I have trouble with pip3 (ImportError: cannot import name 'main' from 'pip'), so prefer to use "python3 -m pip" instead.
+<code bash>
+sudo -H python3 -m pip install --upgrade pip
+sudo -H python3 -m pip install requests
+sudo -H python3 -m pip install numpy
+sudo -H python3 -m pip install matplotlib
+python3 -m pip install --user --upgrade httpie
+</code>
+===== Weird hack for impyla =====
+Refers to https://stackoverflow.com/questions/43918993/python-buildpack-fatal-error-sasl-sasl-h-no-such-file-or-directory
+<code bash>
+sudo python3 -m pip install --no-deps impyla
+sudo python3 -m pip install --no-deps git+https://github.com/snowch/thrift_sasl
+# sudo python3 -m pip install thriftpy
+</code>
+===== MatPlotLib =====
+There's another note on MatPlotLib over at my [[wsl]] page. For the first time on a Macintosh, I had to set the MatPlotLib backend to 'MacOSX'. Otherwise the plot window would appear but not draw any lines.
+<code python>
+import matplotlib
+matplotlib.use('MacOSX')
 </code>