Linux Install Python3.6 and Guide to Pit Avoidance

The installation of Python3

1. Install the dependency environment

Python3 may use various libraries during the installation process, so you need to install these libraries before you can officially install Python3.

yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel

2. Download the ES11en3 source code

There are two ways to download the source code of Python3. The first way is to download the source code from its official website, which is as follows:

https://www.python.org/downloads/source/

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The other way is through wget directly download, such as the following command:

wget https://www.python.org/ftp/python/3.6.1/Python-3.6.1.tgz

3. Create the installation directory

/usr/local/python3: /usr/local/python3

mkdir -p /usr/local/python3

4. Unzip the source package

Unzip the source code package downloaded in Step 2. The command is:

tar -zxvf Python-3.6.1.tgz

5. Compile source code

First enter the unzip source code package directory, and then configure:

cd Python-3.6.1
./configure --prefix=/usr/local/python3

Then compile and install:

make
make install

6. Establish a soft link for Python3

ln -s /usr/local/python3/bin/python3 /usr/bin/python3

7. To add/usr local/python3 / bin PATH

Edit bash_profile to modify the environment variable:

vim ~/.bash_profile

Add the startup directory for Python3 under the PATH variable:

# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
  . ~/.bashrc
fi
# User specific environment and startup programs
PATH=$PATH:$HOME/bin:/usr/local/python3/bin
export PATH

After finishing the changes, press ES76en, and then enter: ES77en to save and exit.

8. Check whether Python3 and Pip3 are normally available

Execute the following command (note: V is uppercase V), and if you see a result of 1, it means that Python3 has been successfully installed.

[alvin@VM_0_16_centos ~]$ python3 -V
Python 3.6.1
[alvin@VM_0_16_centos ~]$ pip3 -V
pip 9.0.1 from /usr/local/lib/python3.6/site-packages (python 3.6)

Avoid pit guide

In fact, for the installation of Python3, there are too many posts on the network, the steps are actually much the same. However, after the actual start to install, more or less will encounter some trouble, especially for the novice. Here are some common pits:

Pit 1: configure: error: no acceptable C compiler found in $PATH

The problem is relatively simple, is the lack of ES106en compilation environment. To install gcc:

yum install -y gcc

In addition, of course, the use of source code installation can also be.

Pit 2: zipimport.ZipImportError: can't decompress data

This problem is caused by the lack of zlib related toolkit, the relevant dependencies can be packaged:

yum -y install zlib*

After installation and then recompile the source code, you can solve.

Pit 3: pip3: Can't connect HTTPS URL because the SSL module is not available

Because in this issue. / configure process, if did not add � with ssl parameter, the default installation of the software involves ssl function is not available, just need ssl pip3 process module, and because there is no specified, so this feature is not available. The solution is as follows:

cd Python-3.6.2
./configure --with-ssl
make
sudo make install

Pit 4: Multilib version problems

This is obvious: multiple versions of the same library. Just delete the extra version.

First query the existing version (in the case of openssl, check which one conflicts)

# rpm -qa | grep openssl
openssl-devel-1.0.0-27.el6_4.2.x86_64
openssl-1.0.0-27.el6_4.2.x86_64
openssl-1.0.0-27.el6_4.2.i686

openssl-1.0.0-27.el6_4.2.x86_64 and openssl-1.0.0-27.el6_4.2.i686:

-1.0.0-27.el6_4.

rpm --erase --nodeps openssl-1.0.0-27.el6_4.2.i686

openssl: openssl:

# yum update "openssl*"

Query 1 openssl, problem solved!

# rpm -qa | grep openssl
openssl-devel-1.0.1e-16.el6_5.7.x86_64
openssl-1.0.1e-16.el6_5.7.x86_64

conclusion