How do you see the entire command history in interactive Python?
I'm working on the default python interpreter on Mac OS X开发者_如何转开发, and I Cmd+K (cleared) my earlier commands. I can go through them one by one using the arrow keys. But is there an option like the --history option in bash shell, which shows you all the commands you've entered so far?
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.
Use readline.get_current_history_length()
to get the length, and readline.get_history_item()
to view each.
With python 3 interpreter the history is written to
~/.python_history
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.
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.
Since the above only works for python 2.x for python 3.x (specifically 3.5) is similar but with a slight modification:
import readline
for i in range(readline.get_current_history_length()):
print (readline.get_history_item(i + 1))
note the extra ()
(using shell scripts to parse .python_history or using python to modify the above code is a matter of personal taste and situation imho)
@Jason-V, it really help, thanks. then, i found this examples and composed to own snippet.
#!/usr/bin/env python3
import os, readline, atexit
python_history = os.path.join(os.environ['HOME'], '.python_history')
try:
readline.read_history_file(python_history)
readline.parse_and_bind("tab: complete")
readline.set_history_length(5000)
atexit.register(readline.write_history_file, python_history)
except IOError:
pass
del os, python_history, readline, atexit
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.
This should give you the commands printed out in separate lines:
import readline
map(lambda p:print(readline.get_history_item(p)),
map(lambda p:p, range(readline.get_current_history_length()))
)
Rehash of Doogle's answer that doesn't printline numbers, but does allow specifying the number of lines to print.
def history(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:
for r in range(1,hlen+1) if not lastn else range(1, hlen+1)[-lastn:]:
print(readline.get_history_item(r))
else:
for r in range(1, -lastn + 1):
print(readline.get_history_item(r))
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