How to repeat last command in python interpreter shell?

Question

How do I repeat the last command? The usual keys: Up, Ctrl+Up, Alt-p don't work. They produce nonsensical characters.

(ve)[kakarukeys@localhost ve]$ python
Python 2.6.6 (r266:84292, Nov 15 2010, 21:48:32) 
[GCC 4.4.4 20100630 (Red Hat 4.4.4-10)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print "hello world"
hello world
>>> ^[[A
  File "<stdin>", line 1
    ^
SyntaxError: invalid syntax
>>> ^[[1;5A
  File "<stdin>", line 1
    [1;5A
    ^
SyntaxError: invalid syntax
>>> ^[p
  File "<stdin>", line 1
    p
    ^
SyntaxError: invalid syntax
>>> 

Solution 1

I use the following to enable history on python shell.

This is my .pythonstartup file . PYTHONSTARTUP environment variable is set to this file path.

# python startup file 
import readline 
import rlcompleter 
import atexit 
import os 
# tab completion 
readline.parse_and_bind('tab: complete') 
# history file 
histfile = os.path.join(os.environ['HOME'], '.pythonhistory') 
try: 
    readline.read_history_file(histfile) 
except IOError: 
    pass 
atexit.register(readline.write_history_file, histfile) 
del os, histfile, readline, rlcompleter

You will need to have the modules readline, rlcompleter to enable this.

Check out the info on this at : http://docs.python.org/using/cmdline.html#envvar-PYTHONSTARTUP.

Modules required:

1. http://docs.python.org/library/readline.html
2. http://docs.python.org/library/rlcompleter.html

Solution 2

In IDLE, go to Options -> Configure IDLE -> Keys and there select history-next and then history-previous to change the keys.

Then click on Get New Keys for Selection and you are ready to choose whatever key combination you want.

Solution 3

Alt + p for previous command from histroy, Alt + n for next command from history.

This is default configure, and you can change these key shortcut at your preference from Options -> Configure IDLE.

Solution 4

You didn't specify which environment. Assuming you are using IDLE.

From IDLE documentation: Command history:

Alt-p retrieves previous command matching what you have typed.
Alt-n retrieves next.
      (These are Control-p, Control-n on the Mac)
Return while cursor is on a previous command retrieves that command.
Expand word is also useful to reduce typing.

Solution 5

By default use ALT+p for previous command, you can change to Up-Arrow instead in IDLE GUi >> OPtions >> Configure IDLE >>Key >>Custom Key Binding It is not necesary to run a custom script, besides readlines module doesnt run in Windows. Hope That Help. :)

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Comments

[pyfunc]

@user496852: Just set the env variable PYTHONSTARTUP to the filepath containing above code. Also check, if you have the required modules.

[Timofey]

it is not necessary, just follow instruction of basak's answer and assign key bindings

[creativeby]

For further information: docs.python.org/2/library/idle.html#python-shell-window

[ctzdev]

For anyone who encounters this problem, I am on 14.04 and was still able to use this solution to fix this problem going from 3.4.0 to 3.4.2.

[Ziggy Eunicien]

'pip install readline' worked for me. All my control sequences were coming out with bracket prefixes on Centos 7 after python 3.4 manual install

[user1063287]

For searchers, this works in Linux Mint 17 Cinnamon too.

[Rob Watts]

I needed to do sudo pip install readline after this to get it to work (python 2.7.11)

[John Doe]

This is the solution I am looking for in IDLE. Up arrow worked on python interpreter launched from bash shell.

[jyao]

works for windows 10, python 3.6.1 as well. Thanks a lot, this is clean and clear, esp. useful for new learners.

[user32882]

An overkill. Just do alt+p

[Davidson Lima]

Most appropriate answer. Should have been chosen as the correct one.

[DaniPaniz]

"Could not find a version that satisfies the requirement py-readline (from versions: ) No matching distribution found for py-readline" I hate this world

[DaniPaniz]

there is no Options -> Configure IDLE for Python 2.7 :/

[DaniPaniz]

I needed to go to settings/preferences (python 2.7, IDLE for mac) and there I found the history-next, thanks so much you are the best :)

[DaniPaniz]

it's called history-next / history-previous

[not2qubit]

Make sure you use pip2 or pip3, depending on what version you have installed.

[Andriy Makukha]

Installing libncurses5-dev and libncursesw5-dev was sufficient to fix my Python 3.5 installation, but Python 3.6 broke up after I installed readline module for it. Probably need to recompile.

[Eduard]

does not work, the old shortcut persists even after resetting.

[ashleedawg]

this asks if I want to print

[Roman]

To get to IDLE, run idle3 in shell

[akpp]

It helped me Ubuntu 18.04 python version 3.7.3 pip install readline

[Zim]

This didn't work for me: UnicodeEncodeError: 'ascii' codec can't encode character u'\uf700' in position 0: ordinal not in range(128) UnicodeEncodeError: 'ascii' codec can't encode character u'\uf701' in position 0: ordinal not in range(128)

[osjerick]

This worked for me on 64-bit Ubuntu 16 as well. I have 32-bit Python 3.5.2, compiled and installed from sources, in addition to the already apt-installed 64-bit Pythons. Just did sudo apt-get install libncurses-dev libncurses-dev:i386 libreadline-dev libreadline-dev:i386 and reinstalled the source-built Python.

[Gulzar]

what's IDLE? How do do this in pycharm console?

[Wolfgang Kuehn]

This breaks python for version 3.8. Do not install!

[not2qubit]

If arrow-up doesn't work, you need to fix your installation. Probably need pyreadline.

[not2qubit]

@WolfgangKuehn Have any bug issue been filed about this to their repo? (if not, please file it.) Sound pretty serious.

[Wolfgang Kuehn]

@not2qubit I have not. This issue was on a compiled Python 3.8.6 on a current Amazon Linux 2. I still don't know why readline is not working (lib missing, compile switch, etc.), haven't got the time.

[Shlomo Gottlieb]

As a Windows user, I had to first install pyreadline, and change the histfile definition by using histfile = pathlib.Path.home().joinpath('.pythonhistory').

[kiriloff]

How to put it to "bottom arrow" as in a bash shell ?

[Alan]

Indeed, on Windows, with Python 3.9, "pip install pyreadline" was all it took to make up-arrow fetch the previous comment, which wasn't happening previously. Thanks.

[not2qubit]

pyreadline is dead meat. Use pyreadline3 which now works with Py3.10.

[not2qubit]

Use pyreadline3 which now works with Py3.10.

[pretzlstyle]

How does one change these bindings? I'm just using python in bash, not IDLE. Alt+p,n works. I'd like them to be mapped to up/down arrows. This works fine in bash.