I find myself frequently using Python's interpreter to work with databases, files, etc -- basically a lot of manual formatting of semi-structured data. I don't properly save and clean up the useful bits as often as I would like. Is there a way to save my input into the shell (db connections, variable assignments, little for loops and bits of logic) -- some history of the interactive session? If I use something like script I get too much stdout noise. I don't really need to pickle all the objects -- though if there is a solution that does that, it would be OK. Ideally I would just be left with a script that ran as the one I created interactively, and I could just delete the bits I didn't need. Is there a package that does this, or a DIY approach?
IPython is extremely useful if you like using interactive sessions. For example for your use-case there is the %save magic command, you just input %save my_useful_session 10-20 23 to save input lines 10 to 20 and 23 to my_useful_session.py (to help with this, every line is prefixed by its number).
Furthermore, the documentation states:
This function uses the same syntax as %history for input ranges, then saves the lines to the filename you specify.
This allows for example, to reference older sessions, such as
%save current_session ~0/
%save previous_session ~1/
Look at the videos on the presentation page to get a quick overview of the features.
From Andrew Jones's website (archived):
import readline
readline.write_history_file('/home/ahj/history')
There is a way to do it. Store the file in ~/.pystartup...
# Add auto-completion and a stored history file of commands to your Python
# interactive interpreter. Requires Python 2.0+, readline. Autocomplete is
# bound to the Esc key by default (you can change it - see readline docs).
#
# Store the file in ~/.pystartup, and set an environment variable to point
# to it: "export PYTHONSTARTUP=/home/user/.pystartup" in bash.
#
# Note that PYTHONSTARTUP does *not* expand "~", so you have to put in the
# full path to your home directory.
import atexit
import os
import readline
import rlcompleter
historyPath = os.path.expanduser("~/.pyhistory")
def save_history(historyPath=historyPath):
import readline
readline.write_history_file(historyPath)
if os.path.exists(historyPath):
readline.read_history_file(historyPath)
atexit.register(save_history)
del os, atexit, readline, rlcompleter, save_history, historyPath
and then set the environment variable PYTHONSTARTUP in your shell (e.g. in ~/.bashrc):
export PYTHONSTARTUP=$HOME/.pystartup
You can also add this to get autocomplete for free:
readline.parse_and_bind('tab: complete')
Please note that this will only work on *nix systems. As readline is only available in Unix platform.
If you are using IPython you can save to a file all your previous commands using the magic function %history with the -f parameter, p.e:
%history -f /tmp/history.py
After installing Ipython, and opening an Ipython session by running the command:
ipython
from your command line, just run the following Ipython 'magic' command to automatically log your entire Ipython session:
%logstart
This will create a uniquely named .py file and store your session for later use as an interactive Ipython session or for use in the script(s) of your choosing.
Also, reinteract gives you a notebook-like interface to a Python session.
In addition to IPython, a similar utility bpython has a "save the code you've entered to a file" feature
I had to struggle to find an answer, I was very new to iPython environment.
This will work
If your iPython session looks like this
In [1] : import numpy as np
....
In [135]: counter=collections.Counter(mapusercluster[3])
In [136]: counter
Out[136]: Counter({2: 700, 0: 351, 1: 233})
You want to save lines from 1 till 135 then on the same ipython session use this command
In [137]: %save test.py 1-135
This will save all your python statements in test.py file in your current directory ( where you initiated the ipython).
There is %history magic for printing and saving the input history (and optionally the output).
To store your current session to a file named my_history.py:
>>> %hist -f my_history.py
History IPython stores both the commands you enter, and the results it produces. You can easily go through previous commands with the up- and down-arrow keys, or access your history in more sophisticated ways.
You can use the %history magic function to examine past input and output. Input history from previous sessions is saved in a database, and IPython can be configured to save output history.
Several other magic functions can use your input history, including %edit, %rerun, %recall, %macro, %save and %pastebin. You can use a standard format to refer to lines:
%pastebin 3 18-20 ~1/1-5
This will take line 3 and lines 18 to 20 from the current session, and lines 1-5 from the previous session.
See %history? for the Docstring and more examples.
Also, be sure to explore the capabilities of %store magic for lightweight persistence of variables in IPython.
Stores variables, aliases and macros in IPython’s database.
d = {'a': 1, 'b': 2}
%store d # stores the variable
del d
%store -r d # Refresh the variable from IPython's database.
>>> d
{'a': 1, 'b': 2}
To autorestore stored variables on startup, specifyc.StoreMagic.autorestore = True in ipython_config.py.
The %history command is awesome, but unfortunately it won't let you save things that were %paste 'd into the sesh. To do that I think you have to do %logstart at the beginning (although I haven't confirmed this works).
What I like to do is
%history -o -n -p -f filename.txt
which will save the output, line numbers, and '>>>' before each input (o, n, and p options). See the docs for %history here.
Just putting another suggesting in the bowl:
Spyder
It has History log and Variable explorer. If you have worked with MatLab, then you'll see the similarities.
As far as Linux goes, one can use script command to record the whole session. It is part of util-linux package so should be on most Linux systems . You can create and alias or function that will call script -c python and that will be saved to a typescript file. For instance, here's a reprint of one such file.
$ cat typescript
Script started on Sat 14 May 2016 08:30:08 AM MDT
Python 2.7.6 (default, Jun 22 2015, 17:58:13)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print 'Hello Pythonic World'
Hello Pythonic World
>>>
Script done on Sat 14 May 2016 08:30:42 AM MDT
Small disadvantage here is that the script records everything , even line-feeds, whenever you hit backspaces , etc. So you may want to use col to clean up the output (see this post on Unix&Linux Stackexchange) .
there is another option --- pyslice.
in the "wxpython 2.8 docs demos and tools", there is a open source program named "pyslices".
you can use it like a editor, and it also support using like a console ---- executing each line like a interactive interpreter with immediate echo.
of course, all the blocks of codes and results of each block will be recorded into a txt file automatically.
the results are logged just behind the corresponding block of code. very convenient.
In IPython, I first use
In [2]: %hist
to view my past code. I select the chunk I want to save and then paste it into file my_file.py using the %%file magic (short for %%writefile)
In [3]: %%file my_file.py
...: # paste code here
...:
...:
hitting return two times in the end.
To append to file use the option -a: %%file -a my_file.py.
If needed, I can list, edit, etc. the file in the underlying command line using the exclamation mark
In [5]: !ls -l my_file.py
In [6]: !vi my_file.py
Some comments were asking how to save all of the IPython inputs at once. For %save magic in IPython, you can save all of the commands programmatically as shown below, to avoid the prompt message and also to avoid specifying the input numbers.
currentLine = len(In)-1
%save -f my_session 1-$currentLine
The -f option is used for forcing file replacement and the len(IN)-1 shows the current input prompt in IPython, allowing you to save the whole session programmatically.
For those using spacemacs, and ipython that comes with python-layer, save magic creates a lot of unwanted output, because of the constant auto-completion command working in the backround such as:
len(all_suffixes)
';'.join(__PYTHON_EL_get_completions('''len'''))
';'.join(__PYTHON_EL_get_completions('''all_substa'''))
len(all_substantives_w_suffixes)
';'.join(__PYTHON_EL_get_completions('''len'''))
';'.join(__PYTHON_EL_get_completions('''all'''))
';'.join(__PYTHON_EL_get_completions('''all_'''))
';'.join(__PYTHON_EL_get_completions('''all_w'''))
';'.join(__PYTHON_EL_get_completions('''all_wo'''))
';'.join(__PYTHON_EL_get_completions('''all_wor'''))
';'.join(__PYTHON_EL_get_completions('''all_word'''))
';'.join(__PYTHON_EL_get_completions('''all_words'''))
len(all_words_w_logograms)
len(all_verbs)
To avoid this just save the ipython buffer like you normally save any other: spc f s
If you use bpython, all your command history is by default saved to ~/.pythonhist.
To save the commands for later reusage you can copy them to a python script file:
$ cp ~/.pythonhist mycommands.py
Then edit that file to clean it up and put it under Python path (global or virtual environment's site-packages, current directory, mentioning in *.pth, or some other way).
To include the commands into your shell, just import them from the saved file:
>>> from mycommands import *
I'd like to suggest another way to maintain python session through tmux on linux. you run tmux, attach your self to the session you opened (if not attached after opening it directly). execute python and do whatever you are doing on it. then detach from session. detaching from a tmux session does not close the session. the session remains open.
pros of this method:
you can attach to this session from any other device (in case you can ssh your pc)
cons of this method:
this method does not relinquish the resources used by the opened python session until you actually exist the python interpreter.
To save input and output on XUbuntu:
In XWindows, run iPython from the Xfce terminal app
click Terminal in the top menu bar and look for save contents in the dropdown
I find this saves the input and output, going all the way back to when I opened the terminal. This is not ipython specific, and would work with ssh sessions or other tasks run from the terminal window.
You can use built-in function open: I use it in all of my
programs in which I need to store some history (Including Calculator, etc.)
for example:
#gk-test.py or anything else would do
try: # use the try loop only if you haven't created the history file outside program
username = open("history.txt").readline().strip("\n")
user_age = open("history.txt").readlines()[1].strip("\n")
except FileNotFoundError:
username = input("Enter Username: ")
user_age = input("Enter User's Age: ")
open("history.txt", "w").write(f"{username}\n{user_age}")
#Rest of the code is secret! try it your own!
I would thank to all of them who liked my comments! Thank you for reading this!
Related
On Windows 10, Python 3.6
Let's say I have a command prompt session open (not Python command prompt or Python interactive session) and I've been setting up an environment with a lot of configurations or something of that nature. Is there any way for me to access the history of commands I used in that session with a python module for example?
Ideally, I would like to be able to export this history to a file so I can reuse it in the future.
Example:
Type in command prompt: python savecmd.py
and it saves the history from that session.
You don't need Python at all, use doskey facilities for that, i.e.:
doskey /history
will print out the current session's command history, you can then redirect that to a file if you want to save it:
doskey /history > saved_commands.txt
If you really want to do it from within Python, you can use subprocess.check_output() to capture the command history and then save it to a file:
import subprocess
cmd_history = subprocess.check_output(["doskey", "/history"])
with open("saved_commands.txt", "wb") as f:
f.write(cmd_history)
You're actually asking for 3 different things there.
Getting Python REPL command hisotry
Getting info from "prompt", which I assume is the Powershell or CMD.exe.
Save the history list to a file.
To get the history from inside your REPL, use:
for i in list(range(readline.get_current_history_length())): print(readline.get_history_item(i))
Unfortunately, there is no history in REPL, when using from outside, as above, so you need to find the history file and print it.
To see the history file from powershell:
function see_my_py_history{ cat C:\<path-to>\saved_commands.txt }
Set-Alias -Name seehist -Value see_my_py_history
Frequently, my workflow involves data cleaning/munging in an IPython shell. This has become particularly wonderful since IPython version 5.0 with all the great upgrades to the terminal interface. So, let's say I make an attempt at sprucing up some piece of unstructured data:
In [11]: for i, (num, header, txt) in enumerate(data):
...: header = [e.strip() for e in header.strip().split('\n')]
...: header[4] = header[4].strip(',').split(',')
...: data[i] = (num, header, txt)
...:
Fantastic, it works! But now, I would really like to add this to a script in my editor. If I copy and paste from my terminal, I capture all the junk on the left. I can clean this up more-or-less easily in an editor, but it would be great if I could copy the code directly to my clipboard from the terminal without touching the mouse and without grabbing the extra stuff either. Is there such a functionality in IPython?
You can use the %history magic to extract the interesting parts from your session. They will be shown in terminal without any of the junk.
Example
In [1]: import numpy as np
In [2]: a = np.random(10)
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-2-83ce219ad17b> in <module>()
----> 1 a = np.random(10)
TypeError: 'module' object is not callable
In [3]: a = np.random.random(10)
In [4]: for i in a:
...: print(i)
...:
0.688626523886
[...]
0.341394850998
If I want to save a part of the session above I can use:
In [5]: %history 1 3-4
import numpy as np
a = np.random.random(10)
for i in a:
print(i)
In the example above I used %history 1 3-4 to assemble all the commands I want to keep and omit the ones I do not need (Line 2, the one with the error). Now you have version of your session that can be nicely copied.
Writing a file
You can also directly write this to file using the -f FILENAME as parameter.
In [8]: %history 1 3-4 -f /tmp/foo.py
Be careful though, this will overwrite existing files.
More Details can be found in the documentation of the %history magic.
So, I have finally found a great solution that is essentially exactly what I wanted: Use Vi mode in IPython. On version 5, this requires:
$ ipython --TerminalInteractiveShell.editing_mode=vi
Now I can use handy vi-like visual mode and yank whatever I need!
Which leads to the following new alias in my .bash_profile/.bash_rc:
alias vpython='ipython --TerminalInteractiveShell.editing_mode=vi'
The save magic command [documentation] saves the input lines you want to a file; the -a option is for "append" mode so that the lines are added at the end of the file instead of overwriting the file. I use it all the time.
With your example:
%save -a myfile.py 11
# the '%' is not necessary
save -a myfile.py 11
Then you can keep coding in IPython.
When there is another command you want to write to the same file, you can just type save then use the up arrow to bring back the last use of "save" (so that the -a option and the filename are already there) and just edit the line number.
Note that you can give several lines to save and also line ranges:
save -a myfile.py 15 18 19-25
In the shell you can first convert the IPython file to a regular Python file (.py) and then do the clean up:
http://ipython.org/ipython-doc/3/notebook/nbconvert.html (see --to script format)
You can also download the file in the notebook editor as Python file and perform the cleanup after this step.
I don't think terminal applications really get access to the copy/paste buffer. You're going to have to use the mouse. How do do it depends on what terminal you're using. Most modern terminals have some sort of "rectangular select" or "block select" mode.
With Windows, rectangular select is the default for cmd.exe and Powershell. If you're using Cygwin's mintty, hold Alt and then select the region with the mouse. The same goes for PuTTY.
On Linux (which I don't have in front of me - take these with a grain of salt), xterm doesn't support it, Gnome Terminal uses Ctrl as the modifier, and KDE's Konsole uses Ctrl+Alt.
For OS X Terminal, the Internet tells me that you use ⌘ while clicking.
Other terminals (and GNU Screen) likely have the feature, it's just a matter of figuring out how to activate it.
Is there a way in Python to detect, within a process, where that process is being executed? I have some code that includes the getpass.getpass() function, which is broken in Spyder, and it's annoying to go back and forth between the command line and the IDE all the time. It would be useful if I could add code like:
if not being run from Spyder:
use getpass
else:
use alternative
Here is the solution I ended up using. After reading Markus's answer, I noticed that Spyder adds half a dozen or so environment variables to os.environ with names like SPYDER_ENCODING, SPYDER_SHELL_ID, etc. Detecting the presence of any of these seems relatively unambiguous, compared to detecting the absence of a variable with as generic a name as 'PYTHONSTARTUP'. The code is simple, and works independently of Spyder's startup script (as far as I can tell):
if any('SPYDER' in name for name in os.environ)
# use alternative
else:
# use getpass
Since the string is at the beginning of each environment variable name, you could also use str.startswith, but it's less flexible, and a little bit slower (I was curious):
>>> import timeit
>>> s = timeit.Timer("[name.startswith('SPYDER') for name in os.environ]", "import os")
>>> i = timeit.Timer("['SPYDER' in name for name in os.environ]", "import os")
>>> s.timeit()
16.18333065883474
>>> i.timeit()
6.156869294143846
The sys.executable method may or may not be useful depending on your installation. I have a couple WinPython installations and a separate Python 2.7 installation, so I was able to check the condition sys.executable.find('WinPy') == -1 to detect a folder name in the path of the executable Spyder uses. Since the warning that shows in IDLE when you try to use getpass is less "loud" than it could be, in my opinion, I ended up also checking the condition sys.executable.find('pythonw.exe') == -1 to make it slightly louder. Using sys.executable only, that method looks like:
if sys.executable.find('pythonw.exe') == sys.executable.find('WinPy') == -1:
# use getpass
else:
# use alternative
But since I want this to work on other machines, and it's much more likely that another user would modify their WinPython installation folder name than that they would rename their IDLE executable, my final code uses sys.executable to detect IDLE and os.environ to detect Spyder, providing a "louder" warning in either case and keeping the code from breaking in the latter.
if any('SPYDER' in name for name in os.environ) \
or 'pythonw.exe' in sys.executable:
password = raw_input('WARNING: PASSWORD WILL BE SHOWN ON SCREEN\n\n' * 3
+ 'Please enter your password: ')
else:
password = getpass.getpass("Please enter your password: ")
By default, Spyder uses a startup scrip, see Preferences -> Console -> Adanced setting. This option is usually set to the scientific_startup.py file that loads pylab et al.
The easiest solution is to just add a global variable to the file and then use that in your if statement, e.g. add this line at the end of scientific_startup.py:
SPYDER_IDE_ACTIVE = True
In your script:
if not 'SPYDER_IDE_ACTIVE' in globals():
use getpass
else:
use alternative
This will work without throwing an error. You can also use exceptions if you like that more.
A second solution would be (if you cannot modify that file for some reason) to just check if the environment variable PYTHONSTARTUP is set. On my machine (using the Anaconda Python stack), it is not set for a regular Python shell. You could do
import os
if not 'PYTHONSTARTUP' in os.environ:
use getpass
else:
use alternative
Spyder provides the option of executing the current editor script in a native system terminal. This would produce identical behavior as if you were running from the command line. To set this up, open the Run Settings dialog by hitting F6. Then select the radio button "Execute in an external System terminal". Now run the script as usual by hitting F5. You should be able to use getpass in the normal fashion with this approach.
You could add env variable when running in Spyder and check it in code.
It would be useful to save the session variables which could be loaded easily into memory at a later stage.
In [23]: %logstart /tmp/session.log
Activating auto-logging. Current session state plus future input saved.
Filename : /tmp/session.log
Mode : backup
Output logging : False
Raw input log : False
Timestamping : False
State : active
In [24]: x = 1
In [25]: %logstop
In [26]: quit()
Do you really want to exit ([y]/n)? y
Then we can restore the session with:
% ipython -log /tmp/session.log
Activating auto-logging. Current session state plus future input saved.
Filename : ipython_log.py
...
In [1]: x
Out[1]: 1
For more on "Session logging and restoring" see the docs.
Note that this merely stores the commands run by IPython. It does not save the
state of the IPython session. Restoring the session requires re-execution of
the commands.
If you set the PYTHONSTARTUP environment variable to point at a file called, say, startup.py:
PYTHONSTARTUP=/path/to/startup.py
then put the following in /path/to/startup.py:
try:
# https://stackoverflow.com/a/5377051/190597 (Tom Dunham)
__IPYTHON__
except NameError:
pass
else:
# https://stackoverflow.com/a/15898875/190597 (user2261139)
from IPython import get_ipython
ipython = get_ipython()
ipython.magic("%logstart /tmp/session.log")
then IPython will call %logstart automatically whenever you start an interactive session.
Looking for something similar I came across save_ipython_variables:
save-ipython-variables lets you ... save your global IPython
variables to disk easily, and load them back into the global
namespace when you need them again, even in a whole new IPython
session.
I haven't had much chance to use it yet, but looks promising.
I haven't tried this yet, but starting from AE Drew's answer, I found a possible alternative. Looks like IPython has a built in magic command that does this called %store:
%store magic for lightweight persistence. Stores variables, aliases and macros in IPython’s database. To automatically restore stored variables at startup, add this to your ipython_config.py file:
c.StoreMagic.autorestore = True
There is also a magic command, history, that can be used to write all the commands/statements given by user.
Syntax : %history -f file_name.
Also %save file_name start_line-end_line, where star_line is the starting line number and end_line is ending line number. Useful in case of selective save.
%run can be used to execute the commands in the saved file
Not my solution, but this seems to be the closest solution, if you are using ipython: https://stackoverflow.com/a/28552465/4752883
I have a .pythonrc in my path, which gets loaded when I run python:
python
Loading pythonrc
>>>
The problem is that my .pythonrc is not loaded when I execute files:
python -i script.py
>>>
It would be very handy to have tab completion (and a few other things) when I load things interactively.
From the Python documentation for -i:
When a script is passed as first argument or the -c option is used, enter interactive mode after executing the script or the command, even when sys.stdin does not appear to be a terminal. The PYTHONSTARTUP file is not read.
I believe this is done so that scripts run predictably for all users, and do not depend on anything in a user's particular PYTHONSTARTUP file.
As Greg has noted, there is a very good reason why -i behaves the way it does. However, I do find it pretty useful to be able to have my PYTHONSTARTUP loaded when I want an interactive session. So, here's the code I use when I want to be able to have PYTHONSTARTUP active in a script run with -i.
if __name__ == '__main__':
#do normal stuff
#and at the end of the file:
import sys
if sys.flags.interactive==1:
import os
myPythonPath = os.environ['PYTHONSTARTUP'].split(os.sep)
sys.path.append(os.sep.join(myPythonPath[:-1]))
pythonrcName = ''.join(myPythonPath[-1].split('.')[:-1]) #the filename minus the trailing extension, if the extension exists
pythonrc = __import__(pythonrcName)
for attr in dir(pythonrc):
__builtins__.__dict__[attr] = getattr(pythonrc, attr)
sys.path.remove(os.sep.join(myPythonPath[:-1]))
del sys, os, pythonrc
Note that this is fairly hacky and I never do this without ensuring that my pythonrc isn't accidentally clobbering variables and builtins.
Apparently the user module provides this, but has been removed in Python 3.0. It is a bit of a security hole, depending what's in your pythonrc...
In addition to Chinmay Kanchi and Greg Hewgill's answers, I'd like to add that IPython and BPython work fine in this case. Perhaps it's time for you to switch? :)