In linux, the arrow keys don't work when I try to enter data for an input() function. I get escape characters. See below (when I pressed left arrow key).
dp@hp:~$ python3 -c "x = input('enter a number '); print(x)"
enter a number 123^[[D^[[D
I have readline installed (I am able to import it in the python shell).
The arrow keys work fine in the interactive interpreter but not in the above case (or when I execute input() from a script).
What could be the reason?
The documentation says:
If the readline module was loaded, then input() will use it to provide elaborate line editing and history features.
In your example, you haven't loaded the readline module. Compare the behavior of this:
x = input('enter a number:')
print(x)
To this:
import readline
x = input('enter a number:')
print(x)
The second example will behave as you expect (readline support is active, arrow keys work, etc) while the first example will not have readline support.
On the command line, this would be:
python3 -c "import readline; x=input('enter a number '); print(x)"
readline works. But it should work otherwise too since I have it installed. I am going to try a pip install to see if readline was installed properly.
import the module to activate the readline support in the input function. The documentation says explicitly that the readline module must be "loaded".readline whenever I use input()? This was not needed on Windows...I use linux too and for any module you have to import it.
For example for the readline module I have to do
import readline
This applies to all modules even the os or sys module I have to do
import os
import sys
However this only applies to modules that you installed correctly. If you installed readline incorrectly not even
import readline
will work.
That means for you
python3 -c "import readline; x = input('enter a number '); print(x)"
if you are doing it straight from the console and this applies to not only readline but every other module that you have and will get.
sys.argv[1:]) instead of usinginput()interactively.