How to use/install python 2to3?

Question

From this https://docs.python.org/3.4/library/2to3.html it says that 2to3 should be installed as a script alongside the python interpreter. However, in my /usr/bin/ folder there are no 2to3 executable, and running find from / finds no 2to3 executable either. I do however have a folder called lib2to3 at /usr/lib64/python{3.4/2.7}/lib2to3 but containing nothing I found relevant. In python/site-packages/setuptools/ there is a lib2to3_ex.py script, but nothing happens if I run it. How do I get to the point where I can simply type 2to3 upgradethisscripttopython3.py ?

Ectophyte

Have you looked in Tools/scripts, per the docs? What happens if you just type 2to3 in the command line and hit return? – Bulky

Tools/scripts often is not in your PATH, you might want to add it. – Wise

I don't have the Tools/scripts path :S , and as far I have found out, the Tools/scripts files are downloaded with the python2.7-examples package in Ubuntu, but so far I haven't found the equivalent package for opensuse (which I'm using) – Ectophyte

Answer 1

You need to first install the following packages:

apt install 2to3
apt install python3-lib2to3
apt install python3-toolz

For windows just install 2to3

pip install 2to3

Then, You can simply go to that directory your python file is in and type the following command:

2to3 ./filename.py

OR for writing the updated python 3 code to the existing file

2to3 . -w

This last will convert all the python files that are in the directory.

Paratroops

toolz is unrelated to lib2to3 – Agneta

In Windows, I seemed to only need 2to3, not the other 2 packages. – Plumbery

The pip variant can be used not only on Windows. – Garret

Answer 2

So the solution is that at least not for me, the Tools/scripts files were not automatically installed. On ubuntu this would be solved by installing python-examples which on opensuse is called python-demo

Ectophyte

on Fedora/RedHat yum install python-tools – Goodale

And on newer versions of Ubuntu, apt-get install 2to3. – Teodora

Answer 3

On CentOS (and other RHEL-like distros) you will need to run yum install python-tools, which installs 2to3 to /usr/bin/2to3

Reorientation

On RHEL8 / CentOS Stream release 8 install platform-python-devel – Kersey

Answer 4

So far I've been using pip install 2to3. Conversions worked like absolute charm! (I'm on Ubuntu 18.04)

Triplenerved

Answer 5

On Fedora 29, the python-tools is not providing 2to3. I had to install the development package:

dnf install python3-devel

I found this out by first calling:

dnf whatprovides /usr/bin/2to3

Cub

Answer 6

Check if you have the file /usr/bin/2to3-2.7 (or similar). If one exists, then simply create a symbolic link to it with a link name of 2to3 (e.g.: ln -s 2to3-2.7 /usr/bin/2to3).

Gazelle