Python 实用宝典

Question 1

I’m trying to install python3 on RHEL using the following steps:

yum search python3

Which returned No matches found for: python3

Followed by:

yum search python

None of the search results contained python3. What should I try next?

Question 2

It is easy to install it manually:

Download (there may be newer releases on Python.org):

$ wget https://www.python.org/ftp/python/3.4.3/Python-3.4.3.tar.xz

Unzip
```
$ tar xf Python-3.* 
$ cd Python-3.*
```
Prepare compilation
```
$ ./configure
```
Build
```
$ make
```
Install
```
$ make install
```
OR if you don’t want to overwrite the python executable (safer, at least on some distros yum needs python to be 2.x, such as for RHEL6) – you can install python3.* as a concurrent instance to the system default with an altinstall:
```
$ make altinstall
```

Now if you want an alternative installation directory, you can pass --prefix to the configurecommand.

Example: for ‘installing’ Python in /opt/local, just add --prefix=/opt/local.

After the make install step: In order to use your new Python installation, it could be, that you still have to add the [prefix]/bin to the $PATH and [prefix]/lib to the $LD_LIBRARY_PATH (depending of the --prefix you passed)

Question 3

Installing from RPM is generally better, because:

you can install and uninstall (properly) python3.
the installation time is way faster. If you work in a cloud environment with multiple VMs, compiling python3 on each VMs is not acceptable.

Solution 1: Red Hat & EPEL repositories

Red Hat has added through the EPEL repository:

Python 3.4 for CentOS 6
Python 3.6 for CentOS 7

[EPEL] How to install Python 3.4 on CentOS 6

sudo yum install -y epel-release
sudo yum install -y python34

# Install pip3
sudo yum install -y python34-setuptools  # install easy_install-3.4
sudo easy_install-3.4 pip

You can create your virtualenv using pyvenv:

pyvenv /tmp/foo

[EPEL] How to install Python 3.6 on CentOS 7

With CentOS7, pip3.6 is provided as a package :)

sudo yum install -y epel-release
sudo yum install -y python36 python36-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

If you use the pyvenv script, you’ll get a WARNING:

$ pyvenv-3.6 /tmp/foo
WARNING: the pyenv script is deprecated in favour of `python3.6 -m venv`

Solution 2: IUS Community repositories

The IUS Community provides some up-to-date packages for RHEL & CentOS. The guys behind are from Rackspace, so I think that they are quite trustworthy…

https://ius.io/

Check the right repo for you here:

https://ius.io/setup

[IUS] How to install Python 3.6 on CentOS 6

sudo yum install -y https://repo.ius.io/ius-release-el6.rpm
sudo yum install -y python36u python36u-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

[IUS] How to install Python 3.6 on CentOS 7

sudo yum install -y https://repo.ius.io/ius-release-el7.rpm
sudo yum install -y python36u python36u-pip

You can create your virtualenv using pyvenv:

python3.6 -m venv /tmp/foo

Question 4

In addition to gecco’s answer I would change step 3 from:

./configure

to:

./configure --prefix=/opt/python3

Then after installation you could also:

# ln -s /opt/python3/bin/python3 /usr/bin/python3

It is to ensure that installation will not conflict with python installed with yum.

See explanation I have found on Internet:

http://www.hosting.com/support/linux/installing-python-3-on-centosredhat-5x-from-source

Question 5

Along with Python 2.7 and 3.3, Red Hat Software Collections now includes Python 3.4 – all work on both RHEL 6 and 7.

RHSCL 2.0 docs are at https://access.redhat.com/documentation/en-US/Red_Hat_Software_Collections/

Plus lot of articles at developerblog.redhat.com.

edit

Follow these instructions to install Python 3.4 on RHEL 6/7 or CentOS 6/7:

# 1. Install the Software Collections tools:
yum install scl-utils

# 2. Download a package with repository for your system.
#  (See the Yum Repositories on external link. For RHEL/CentOS 6:)
wget https://www.softwarecollections.org/en/scls/rhscl/rh-python34/epel-6-x86_64/download/rhscl-rh-python34-epel-6-x86_64.noarch.rpm
#  or for RHEL/CentOS 7
wget https://www.softwarecollections.org/en/scls/rhscl/rh-python34/epel-7-x86_64/download/rhscl-rh-python34-epel-7-x86_64.noarch.rpm

# 3. Install the repo package (on RHEL you will need to enable optional channel first):
yum install rhscl-rh-python34-*.noarch.rpm

# 4. Install the collection:
yum install rh-python34

# 5. Start using software collections:
scl enable rh-python34 bash

Question 6

Use the SCL repos.

sudo sh -c 'wget -qO- http://people.redhat.com/bkabrda/scl_python33.repo >> /etc/yum.repos.d/scl.repo'
sudo yum install python33
scl enable python27

(This last command will have to be run each time you want to use python27 rather than the system default.)

Question 7

Python3 was recently added to EPEL7 as Python34.

There is ongoing (currently) effort to make packaging guidelines about how to package things for Python3 in EPEL7.

See https://bugzilla.redhat.com/show_bug.cgi?id=1219411
and https://lists.fedoraproject.org/pipermail/python-devel/2015-July/000721.html

Question 8

You can download a source RPMs and binary RPMs for RHEL6 / CentOS6 from here

This is a backport from the newest Fedora development source rpm to RHEL6 / CentOS6

Question 9

I see all the answers as either asking to compile python3 from code or installing the binary RPM package. Here is another answer to enable EPEL (Extra Packages for Enterprise Linux) and then install python using yum. Steps for RHEL 7.5 (Maipo)

yum install wget –y
wget https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/e/epel-release-7-XX.noarch.rpm # Verify actual RPM name by browsing dir over browser
rpm –ivh epel-*.rpm
yum install python36

Also see link

Question 10

I was having the same issue using the python 2.7. Follow the below steps to upgrade successfully to 3.6. You can also try this one-

See before upgrading version is 2.x
```
python --version
Python 2.7.5
```
Use below command to upgrade your python to 3.x version-

yum install python3x

replace x with the version number you want.

i.e. for installing python 3.6 execute
```
yum install python36
```
After that if you want to set this python for your default version then in bashrc file add

vi ~/.bashrc
```
alias python='python3.6'
```
execute bash command to apply the settings
```
bash 
```
Now you can see the version below
```
python --version
Python 3.6.3
```

Question 11

Three steps using Python 3.5 by Software Collections:

sudo yum install centos-release-scl
sudo yum install rh-python35
scl enable rh-python35 bash

Note that sudo is not needed for the last command. Now we can see that python 3 is the default for the current shell:

python --version
Python 3.5.1

Simply skip the last command if you’d rather have Python 2 as the default for the current shell.

Now let’s say that your Python 3 scripts give you an error like /usr/bin/env: python3: No such file or directory. That’s because the installation is usually done to an unusual path:

/opt/rh/rh-python35/root/bin/python3

The above would normally be a symlink. If you want python3 to be automatically added to the $PATH for all users on startup, one way to do this is adding a file like:

sudo vim /etc/profile.d/rh-python35.sh

Which would have something like:

#!/bin/bash

PATH=$PATH:/opt/rh/rh-python35/root/bin/

And now after a reboot, if we do

python3 --version

It should just work. One exception would be an auto-generated user like “jenkins” in a Jenkins server which doesn’t have a shell. In that case, manually adding the path to $PATH in scripts would be one way to go.

Finally, if you’re using sudo pip3 to install packages, but it tells you that pip3 cannot be found, it could be that you have a secure_path in /etc/sudoers. Checking with sudo visudo should confirm that. To temporarily use the standard PATH when running commands you can do, for example:

sudo env "PATH=$PATH" pip3 --version

See this question for more details.

NOTE: There is a newer Python 3.6 by Software Collections, but I wouldn’t recommend it at this time, because I had major headaches trying to install Pycurl. For Python 3.5 that isn’t an issue because I just did sudo yum install sclo-python35-python-pycurl which worked out of the box.

Question 12

If you are on RHEL and want a Red Hat supported Python, use Red Hat Software collections (RHSCL). The EPEL and IUS packages are not supported by Red Hat. Also many of the answers above point to the CentOS software collections. While you can install those, they aren’t the Red Hat supported packages for RHEL.

Also, the top voted answer gives bad advice – On RHEL you do not want to change /usr/bin/python, /usr/bin/python2 because you will likely break yum and other RHEL admin tools. Take a look at /bin/yum, it is a Python script that starts with #!/usr/bin/python. If you compile Python from source, do not do a make install as root. That will overwrite /usr/bin/python. If you break yum it can be difficult to restore your system.

For more info, see How to install Python 3, pip, venv, virtualenv, and pipenv on RHEL on developers.redhat.com. It covers installing and using Python 3 from RHSCL, using Python Virtual Environments, and a number of tips for working with software collections and working with Python on RHEL.

In a nutshell, to install Python 3.6 via Red Hat Software Collections:

$ su -
# subscription-manager repos --enable rhel-7-server-optional-rpms \
   --enable rhel-server-rhscl-7-rpms
# yum -y install @development
# yum -y install rh-python36

# yum -y install rh-python36-numpy \
   rh-python36-scipy \ 
   rh-python36-python-tools \
   rh-python36-python-six

To use a software collection you have to enable it:

scl enable rh-python36 bash

However if you want Python 3 permanently enabled, you can add the following to your ~/.bashrc and then log out and back in again. Now Python 3 is permanently in your path.

# Add RHSCL Python 3 to my login environment
source scl_source enable rh-python36

Note: once you do that, typing python now gives you Python 3.6 instead of Python 2.7.

See the above article for all of this and a lot more detail.

Question 13

If you want official RHEL packages you can use RHSCL (Red Hat Software Collections)

More details:

You have to have access to Red Hat Customer Portal to read full articles.

Question 14

Here are the steps i followed to install Python3:

yum install wget
wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tar.xz  
sudo tar xvf Python-3.*   
cd Python-3.* 
sudo ./configure --prefix=/opt/python3    
sudo make   
sudo make install   
sudo ln -s /opt/python3/bin/python3 /usr/bin/python3

$ /usr/bin/python3    
Python 3.6.0

Question 15

yum install python34.x86_64 works if you have epel-release installed, which this answer explains how to, and I confirmed it worked on RHEL 7.3

$ cat /etc/*-release
NAME="Red Hat Enterprise Linux Server"
VERSION="7.3 (Maipo)

$ type python3
python3 is hashed (/usr/bin/python3)

Question 16

For RHEL on Amazon Linux, using python3 I had to do :

sudo yum install python34-devel

Question 17

Full working 36 when SCL is not available (based on Joys input)

yum install wget –y
wget https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/e/epel-release-7-11.noarch.rpm
rpm –ivh epel-*.rpm
yum install python36

sudo yum install python34-setuptools
sudo mkdir /usr/local/lib/python3.6
sudo mkdir /usr/local/lib/python3.6/site-packages

sudo easy_install-3.6 pip

Finally activate the environment…

pyvenv-3.6 py3
source py3/bin/activate

Then python3

Question 18

You can install miniconda (https://conda.io/miniconda.html). That’s a bit more than just python 3.7 but the installation is very straightforward and simple.

curl https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O
sudo yum install bzip2
bash Miniconda3-latest-Linux-x86_64.sh

You’ll have to accept the license agreement and choose some options in interactive mode (accept the defaults). I believe it can be also installed silently somehow.

Question 19

For those working on AWS EC2 RHEL 7.5, (use sudo) enable required repos

yum-config-manager --enable rhui-REGION-rhel-server-optional
yum-config-manager --enable rhui-REGION-rhel-server-rhscl

Install Python 3.6

yum install rh-python36

Install other dependencies

yum install rh-python36-numpy  rh-python36-scipy  rh-python36-python-tools  rh-python36-python-six

Python 实用宝典

在RHEL上安装Python 3

问题：在RHEL上安装Python 3

回答 0

回答 1

解决方案1：Red Hat和EPEL存储库

[EPEL]如何在CentOS 6上安装Python 3.4

[EPEL]如何在CentOS 7上安装Python 3.6

解决方案2：IUS社区存储库

[IUS]如何在CentOS 6上安装Python 3.6

[IUS]如何在CentOS 7上安装Python 3.6

Solution 1: Red Hat & EPEL repositories

[EPEL] How to install Python 3.4 on CentOS 6

[EPEL] How to install Python 3.6 on CentOS 7

Solution 2: IUS Community repositories

[IUS] How to install Python 3.6 on CentOS 6

[IUS] How to install Python 3.6 on CentOS 7

回答 2

回答 3

请按照以下说明在RHEL 6/7或CentOS 6/7上安装Python 3.4：

Follow these instructions to install Python 3.4 on RHEL 6/7 or CentOS 6/7:

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有趣好用的Python教程