How do you see the entire command history in interactive Python?

Question

I\'m working on the default python interpreter on Mac OS X, and I Cmd+K (cleared) my earlier commands. I can go through them one by one using the arrow

Answer 1

With python 3 interpreter the history is written to
~/.python_history

Answer 2

A simple function to get the history similar to unix/bash version.

Hope it helps some new folks.

def ipyhistory(lastn=None):
    """
    param: lastn Defaults to None i.e full history. If specified then returns lastn records from history.
           Also takes -ve sequence for first n history records.
    """
    import readline
    assert lastn is None or isinstance(lastn, int), "Only integers are allowed."
    hlen = readline.get_current_history_length()
    is_neg = lastn is not None and lastn < 0
    if not is_neg:
        flen = len(str(hlen)) if not lastn else len(str(lastn))
        for r in range(1,hlen+1) if not lastn else range(1, hlen+1)[-lastn:]:
            print(": ".join([str(r if not lastn else r + lastn - hlen ).rjust(flen), readline.get_history_item(r)]))
    else:
        flen = len(str(-hlen))
        for r in range(1, -lastn + 1):
            print(": ".join([str(r).rjust(flen), readline.get_history_item(r)]))

Snippet: Tested with Python3. Let me know if there are any glitches with python2. Samples:

Full History : ipyhistory()

Last 10 History: ipyhistory(10)

First 10 History: ipyhistory(-10)

Hope it helps fellas.

Answer 3

Use readline.get_current_history_length() to get the length, and readline.get_history_item() to view each.

Answer 4

If you want to write the history to a file:

import readline
readline.write_history_file('python_history.txt')

The help function gives:

Help on built-in function write_history_file in module readline:

write_history_file(...)
    write_history_file([filename]) -> None
    Save a readline history file.
    The default filename is ~/.history.

Answer 5

In IPython %history -g should give you the entire command history. The default configuration also saves your history into a file named .python_history in your user directory.

Answer 6

Code for printing the entire history:

Python 3

One-liner (quick copy and paste):

import readline; print('\n'.join([str(readline.get_history_item(i + 1)) for i in range(readline.get_current_history_length())]))

(Or longer version...)

import readline
for i in range(readline.get_current_history_length()):
    print (readline.get_history_item(i + 1))

Python 2

One-liner (quick copy and paste):

import readline; print '\n'.join([str(readline.get_history_item(i + 1)) for i in range(readline.get_current_history_length())])

(Or longer version...)

import readline
for i in range(readline.get_current_history_length()):
    print readline.get_history_item(i + 1)

Note: get_history_item() is indexed from 1 to n.