judy2k

from inspect import signature

def auto_args(f):
    sig = signature(f)  # Get a signature object for the target:
    def replacement(self, *args, **kwargs):
        # Parse the provided arguments using the target's signature:
        bound_args = sig.bind(self, *args, **kwargs)
        # Save away the arguments on `self`:
        for k, v in bound_args.arguments.items():
            if k != 'self':

judy2k

This talk is aimed at intermediate Python developers who are interested in developing & maintaining Python libraries. The audience should understand core Python reasonably well, and be aware of things like the property decorator and what "dunder-methods" are.

The audience will learn how to structure their project and their code in ways that will allow them to make changes later without breaking their users' code. Hopefully they'll come away thinking about the structure of their library code in a clearer way.

judy2k

#!/bin/bash -e
#
# tweet-syntax - Create a syntax-highighted PNG file of your code and save in /tmp
#
# Prerequisites:
#   pip install --upgrade pygments pillow
#   'Source Code Pro' font (or change the script below)
#
# Usage: cat code.ext | tweet-syntax [<syntax>]

judy2k

# So, a bit like mocking/patching, it depends on how the thing you're patching is imported *where it's used*.

# If the code that uses it is in a module called `client`, you'd want to do one of the following:

# If client.py looks like this:
from django.things import victim

def useful_function():
  victim(blah)

judy2k

class NonDataDescriptor(object):
    def __get__(self, *args, **kwargs):
        return 'magic'

class DataDescriptor(object):
    def __get__(self, *args, **kwargs):
        return 'magic'

    def __set__(self, *args, **kwargs):
        pass

judy2k

from transfer_dict import transfer_dict

SOURCE = {
    'a': 'thing',
    'key': 'value',
}

def test_basic():
    dest = transfer_dict(SOURCE)
    assert dest == SOURCE

judy2k

# Please note this function is a sketch and there will be (plenty of) edge cases
# where it won't do the right thing.

def whitelist_dict(d, whitelist):
    """
    Neat function to extract arguments from a dict, d, that are acceptable for
    calling a target function.
    
    `whitelist` can be either a set of acceptable parameter names, or a callable,
    which will have its parameters inspected.

judy2k

from datetime import date, timedelta

def next_weekday(d):
    wd = d.weekday()
    return d + timedelta(days=1 if wd < 4 else 7 - wd)

judy2k

Python & Unicode

text = open('a_unicode_file.txt', 'r').read()
print text
print 'type:', type(text)       # str is a container for binary data
print 'bytes:', len(text)       # The number of bytes, not characters!
print ' '.join(repr(b) for b in text)
print 'first byte:', text[:1] # Prints an invalid character!

judy2k

#!/usr/bin/env python
 
import re
import sys
 
 
def rep(sval):
    return str(int(sval.group()) * 2)
 
if __name__ == '__main__':