PEP8, PyPi, PDB, Python, socket, unicode, URL, urllib2, HTTP, PyLint, Fabric, pip, boltons

Strings

  • Replace accentuated characters by their ASCII equivalent in a unicode string:
import unicodedata

unicodedata.normalize("NFKD", "éèàçÇÉȲ³¼ÀÁÂÃÄÅËÍÑÒÖÜÝåïš™").encode("ascii", "ignore")
  • Cleanest way I found to produce slugified / tokenized strings, based on boltons.strutils:
>>> from boltons import strutils
>>> strutils.slugify(" aBc De F   1 23 4! -- ! 56--78 - -9- %$& +eée-", "-", ascii=True)
b'abc-de-f-1-23-4-56-78-9-eee'

Alternative: use awesome-slugify package.

Sorting

  • Sort a list of dicts by dict-key (source):
import operator

[dict(a=1, b=2, c=3), dict(a=2, b=2, c=2), dict(a=3, b=2, c=1)].sort(
    key=operator.itemgetter("c")
)

Date & Time

I recommend using Arrow. But if you can’t, here are some pure-python snippets.

  • Add a month to the current date:
import datetime
import dateutil

datetime.date.today() + dateutil.relativedelta(months=1)

Network

  • Set urllib2 timeout (source):
import socket

socket.setdefaulttimeout(10)
  • Start a dumb HTTP server on port 8000 (source):
$ python -m SimpleHTTPServer 8000

Debug

import pdb

pdb.set_trace()
  • Delete all .pyc and .pyo files in the system:
$ find / -name "*.py[co]" -print -delete

Version

  • Print Python’s 3-elements version number:
$ python -c "from __future__ import print_function; import sys; print('.'.join(map(str, sys.version_info[:3])))"
2.7.6
  • Compare Python version for use in shell scripts:
$ python -c "import sys; exit(sys.version_info[:3] < (2, 7, 9))"
$ if [[ $? != 0 ]]; then
>     echo "Old Python detected.";
> fi
Old Python detected.

Style

  • Use autopep8 to apply PEP8’s coding style on all Python files:
$ find ./ -iname "*.py" -print -exec autopep8 --in-place "{}" \;

Configuration

I maintain a set of default configuration files in my dotfiles repository:

Package Management

  • Generate a binary distribution of the current package:
$ python ./setup.py sdist
  • Register, generate and upload to PyPi the current package as a source package, an egg and a dumb binary:
$ python ./setup.py register sdist bdist_egg bdist_dumb upload
  • Download Pygments’ source distribution from PyPi, without dependencies (source):
$ pip download --no-binary=:all: --no-deps pygments==2.14.0

from pathlib import Path

from pip._internal.cli.status_codes import SUCCESS
from pip._internal.commands.download import DownloadCommand
from pip._internal.utils.temp_dir import global_tempdir_manager, tempdir_registry


tmp_path = Path("/tmp")

# Emulate the folowwing CLI call:
#   $ pip download --no-binary=:all: --no-deps pygments==2.14.0
cmd = DownloadCommand(name="dummy_name", summary="dummy_summary")

with cmd.main_context():
    cmd.tempdir_registry = cmd.enter_context(tempdir_registry())
    cmd.enter_context(global_tempdir_manager())
    options, args = cmd.parse_args(
        [
            "--no-binary=:all:",
            "--no-deps",
            "--dest",
            f"{tmp_path}",
            f"pygments==2.14.0",
        ]
    )
    cmd.verbosity = options.verbose
    outcome = cmd.run(options, args)
    assert outcome == SUCCESS

package_path = tmp_path.joinpath("Pygments-2.14.0.tar.gz")
assert package_path.is_file()

Jinja

To generate curly braces:

>>> from jinja2 import Template
>>> Template(u""" Yo! """).render()
u' Yo! '
>>> Template(u""" {{'{{'}} """).render()
u' {{ '
>>> Template(u""" {{'{'}} """).render()
u' { '
>>> Template(u""" {{'{'}}machin{{'}'}} """).render()
u' {machin} '

Data