##// END OF EJS Templates
Reset the interactive namespace __warningregistry__ before executing code...
Reset the interactive namespace __warningregistry__ before executing code Fixes #6611. Idea: Right now, people often don't see important warnings when running code in IPython, because (to a first approximation) any given warning will only issue once per session. Blink and you'll miss it! This is a very common contributor to confused emails to numpy-discussion. E.g.: In [5]: 1 / my_array_with_random_contents /home/njs/.user-python2.7-64bit-3/bin/ipython:1: RuntimeWarning: divide by zero encountered in divide #!/home/njs/.user-python2.7-64bit-3/bin/python Out[5]: array([ 1.77073316, -2.29765021, -2.01800811, ..., 1.13871243, -1.08302964, -8.6185091 ]) Oo, right, guess I gotta be careful of those zeros -- thanks, numpy, for giving me that warning! A few days later: In [592]: 1 / some_other_array Out[592]: array([ 3.07735763, 0.50769289, 0.83984078, ..., -0.67563917, -0.85736257, -1.36511271]) Oops, it turns out that this array had a zero in it too, and that's going to bite me later. But no warning this time! The effect of this commit is to make it so that warnings triggered by the code in cell 5 do *not* suppress warnings triggered by the code in cell 592. Note that this only applies to warnings triggered *directly* by code entered interactively -- if somepkg.foo() calls anotherpkg.bad_func() which issues a warning, then this warning will still only be displayed once, even if multiple cells call somepkg.foo(). But if cell 5 and cell 592 both call anotherpkg.bad_func() directly, then both will get warnings. (Important exception: if foo() is defined *interactively*, and calls anotherpkg.bad_func(), then every cell that calls foo() will display the warning again. This is unavoidable without fixes to CPython upstream.) Explanation: Python's warning system has some weird quirks. By default, it tries to suppress duplicate warnings, where "duplicate" means the same warning message triggered twice by the same line of code. This requires determining which line of code is responsible for triggering a warning, and this is controlled by the stacklevel= argument to warnings.warn. Basically, though, the idea is that if foo() calls bar() which calls baz() which calls some_deprecated_api(), then baz() will get counted as being "responsible", and the warning system will make a note that the usage of some_deprecated_api() inside baz() has already been warned about and doesn't need to be warned about again. So far so good. To accomplish this, obviously, there has to be a record of somewhere which line this was. You might think that this would be done by recording the filename:linenumber pair in a dict inside the warnings module, or something like that. You would be wrong. What actually happens is that the warnings module will use stack introspection to reach into baz()'s execution environment, create a global (module-level) variable there named __warningregistry__, and then, inside this dictionary, record just the line number. Basically, it assumes that any given module contains only one line 1, only one line 2, etc., so storing the filename is irrelevant. Obviously for interactive code this is totally wrong -- all cells share the same execution environment and global namespace, and they all contain a new line 1. Currently the warnings module treats these as if they were all the same line. In fact they are not the same line; once we have executed a given chunk of code, we will never see those particular lines again. As soon as a given chunk of code finishes executing, its line number labels become meaningless, and the corresponding warning registry entries become meaningless as well. Therefore, with this patch we delete the __warningregistry__ each time we execute a new block of code.

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mathjax.py
238 lines | 7.0 KiB | text/x-python | PythonLexer
#!/usr/bin/python
"""Utility function for installing MathJax javascript library into
your IPython nbextensions directory, for offline use.
Authors:
* Min RK
* Mark Sienkiewicz
* Matthias Bussonnier
To download and install MathJax:
From Python:
>>> from IPython.external.mathjax import install_mathjax
>>> install_mathjax()
From the command line:
$ python -m IPython.external.mathjax
To a specific location:
$ python -m IPython.external.mathjax -i /usr/share/
will install mathjax to /usr/share/mathjax
To install MathJax from a file you have already downloaded:
$ python -m IPython.external.mathjax mathjax-xxx.tar.gz
$ python -m IPython.external.mathjax mathjax-xxx.zip
It will not install MathJax if it is already there. Use -r to
replace the existing copy of MathJax.
To find the directory where IPython would like MathJax installed:
$ python -m IPython.external.mathjax -d
"""
from __future__ import print_function
#-----------------------------------------------------------------------------
# Copyright (C) 2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import argparse
import os
import shutil
import sys
import tarfile
import zipfile
from IPython.utils.path import get_ipython_dir
try:
from urllib.request import urlopen # Py 3
except ImportError:
from urllib2 import urlopen
#-----------------------------------------------------------------------------
#
#-----------------------------------------------------------------------------
# Where mathjax will be installed
nbextensions = os.path.join(get_ipython_dir(), 'nbextensions')
default_dest = os.path.join(nbextensions, 'mathjax')
# Test for access to install mathjax
def prepare_dest(dest, replace=False):
"""prepare the destination folder for mathjax install
Returns False if mathjax appears to already be installed and there is nothing to do,
True otherwise.
"""
parent = os.path.abspath(os.path.join(dest, os.path.pardir))
if not os.path.exists(parent):
os.makedirs(parent)
if os.path.exists(dest):
if replace:
print("removing existing MathJax at %s" % dest)
shutil.rmtree(dest)
return True
else:
mathjax_js = os.path.join(dest, 'MathJax.js')
if not os.path.exists(mathjax_js):
raise IOError("%s exists, but does not contain MathJax.js" % dest)
print("%s already exists" % mathjax_js)
return False
else:
return True
def extract_tar(fd, dest):
"""extract a tarball from filelike `fd` to destination `dest`"""
# use 'r|gz' stream mode, because socket file-like objects can't seek:
tar = tarfile.open(fileobj=fd, mode='r|gz')
# The first entry in the archive is the top-level dir
topdir = tar.firstmember.path
# extract the archive (contains a single directory) to the destination directory
parent = os.path.abspath(os.path.join(dest, os.path.pardir))
tar.extractall(parent)
# it will be mathjax-MathJax-<sha>, rename to just mathjax
os.rename(os.path.join(parent, topdir), dest)
def extract_zip(fd, dest):
"""extract a zip file from filelike `fd` to destination `dest`"""
z = zipfile.ZipFile(fd, 'r')
# The first entry in the archive is the top-level dir
topdir = z.namelist()[0]
# extract the archive (contains a single directory) to the static/ directory
parent = os.path.abspath(os.path.join(dest, os.path.pardir))
z.extractall(parent)
# it will be mathjax-MathJax-<sha>, rename to just mathjax
d = os.path.join(parent, topdir)
os.rename(os.path.join(parent, topdir), dest)
def install_mathjax(tag='2.4.0', dest=default_dest, replace=False, file=None, extractor=extract_tar):
"""Download and/or install MathJax for offline use.
This will install mathjax to the nbextensions dir in your IPYTHONDIR.
MathJax is a ~15MB download, and ~150MB installed.
Parameters
----------
replace : bool [False]
Whether to remove and replace an existing install.
dest : str [IPYTHONDIR/nbextensions/mathjax]
Where to install mathjax
tag : str ['2.4.0']
Which tag to download. Default is '2.4.0', the current stable release,
but alternatives include 'v1.1a' and 'master'.
file : file like object [ defualt to content of https://github.com/mathjax/MathJax/tarball/#{tag}]
File handle from which to untar/unzip/... mathjax
extractor : function
Method to use to untar/unzip/... `file`
"""
try:
anything_to_do = prepare_dest(dest, replace)
except OSError as e:
print("ERROR %s, require write access to %s" % (e, dest))
return 1
else:
if not anything_to_do:
return 0
if file is None:
# download mathjax
mathjax_url = "https://github.com/mathjax/MathJax/archive/%s.tar.gz" %tag
print("Downloading mathjax source from %s" % mathjax_url)
response = urlopen(mathjax_url)
file = response.fp
print("Extracting to %s" % dest)
extractor(file, dest)
return 0
def main():
parser = argparse.ArgumentParser(
description="""Install mathjax from internet or local archive""",
)
parser.add_argument(
'-i',
'--install-dir',
default=nbextensions,
help='custom installation directory. Mathjax will be installed in here/mathjax')
parser.add_argument(
'-d',
'--print-dest',
action='store_true',
help='print where mathjax would be installed and exit')
parser.add_argument(
'-r',
'--replace',
action='store_true',
help='Whether to replace current mathjax if it already exists')
parser.add_argument('filename',
help="the local tar/zip-ball filename containing mathjax",
nargs='?',
metavar='filename')
pargs = parser.parse_args()
dest = os.path.join(pargs.install_dir, 'mathjax')
if pargs.print_dest:
print(dest)
return
# remove/replace existing mathjax?
replace = pargs.replace
# do it
if pargs.filename:
fname = pargs.filename
# automatically detect zip/tar - could do something based
# on file content, but really not cost-effective here.
if fname.endswith('.zip'):
extractor = extract_zip
else :
extractor = extract_tar
# do it
return install_mathjax(file=open(fname, "rb"), replace=replace, extractor=extractor, dest=dest)
else:
return install_mathjax(replace=replace, dest=dest)
if __name__ == '__main__' :
sys.exit(main())
__all__ = ['install_mathjax', 'main', 'default_dest']