I’ve long wondered what portion of the general public can juggle. I couldn’t
find an answer searching the web, so I used the best polling method I have,
Twitter:
I realize that my Twitter followers skew toward people like me, so I ran a
second poll to try to get data outside of my bubble:
These polls are by no means scientific, and are still very skewed toward the
savvy and educated. If you ask a tech-bubble person to ask a friend, the friend
is still from a small slice of the population as a whole.
But this is the best data we’ve got. I’ll say that in general, 20–30% of
people can juggle.
Since I was making polls, and since 30% was higher than I would have guessed,
I made a third poll to see what other people would guess:
There’s a nice symmetry to the idea that about 70% of people are surprised
that about 30% of people can juggle!
If you have a better source of data about the general public, let me know.
Since Python 3.6, regular dictionaries retain their insertion order: when you
iterate over a dict, you get the items in the same order they were added to the
dict. Before 3.6, dicts were unordered: the iteration order was seemingly
random.
Here are two surprising things about these ordered dicts.
You can’t get the first item
Since the items in a dict have a specific order, it should be easy to get the
first (or Nth) item, right? Wrong. It’s not possible to do this directly. You
might think that d[0] would be the first item, but it’s
not, it’s the value of the key 0, which could be the last item added to the
dict.
The only way to get the Nth item is to iterate over the dict, and wait until
you get to the Nth item. There’s no random access by ordered index. This is
one place where lists are better than dicts. Getting the Nth element of a list
is an O(1) operation. Getting the Nth element of a dict (even if it is ordered)
is an O(N) operation.
OrderedDict is a little different
If dicts are ordered now,
collections.OrderedDict
is useless, right? Well, maybe. It won’t be removed because that would break
code using that class, and it has some methods that regular dicts don’t. But
there’s also one subtle difference in behavior. Regular dicts don’t take order
into account when comparing dicts for equality, but OrderedDicts do:
>>> d1 = {"a": 1, "b": 2}
>>> d2 = {"b": 2, "a": 1}
>>> d1 == d2
True
>>> list(d1)
['a', 'b']
>>> list(d2)
['b', 'a']
>>> from collections import OrderedDict
>>> od1 = OrderedDict([("a", 1), ("b", 2)])
>>> od2 = OrderedDict([("b", 2), ("a", 1)])
>>> od1 == od2
False
>>> list(od1)
['a', 'b']
>>> list(od2)
['b', 'a']
>>>
BTW, this post is the result of a surprisingly long and contentious discussion
in the Python Discord.
Some of my work on the Open edX team at
edX requires working with the three dozen or so
repos that form the backbone of the Open edX software. That often means doing
the same thing to all of them (tagging, logs, etc).
To make it easier to work with a collection of repos, I have a shell function
to run the same command on the git directories found under the current
directory. It gets a little more complicated than that: I might have 100 repos
in the current directory, but only the ones that have certain master branches
should be included in an operation.
My function is called “gittreeif”: it takes a branch name and a command, and
walks the current directory tree looking for git repos that have that branch.
For each one, it executes the command:
$ gittreeif origin/juniper.master git status
I also define “gittree”, which runs on every repo regardless of its
branches.
Here is the definition of gittreeif. Put it in your shell startup file
(.bashrc, .zshrc,
whatever):
# Run a command for every repo found somewhere beneath the current directory.
#
# $ gittree git fetch --all --prune
#
# To only run commands in repos with a particular branch, use gittreeif:
#
# $ gittreeif branch_name git fetch --all --prune
#
# If the command has subcommands that need to run in each directory, quote the
# entire command:
#
# $ gittreeif origin/foo 'git log --format="%s" origin/foo ^$(git merge-base origin/master origin/foo)'
#
# The directory name is printed before each command. Use -q to suppress this,
# or -r to show the origin remote url instead of the directory name.
#
# $ gittreeif origin/foo -q git status
#
gittreeif() {
local test_branch="$1"
shift
local show_dir=true show_repo=false
if [[ $1 == -r ]]; then
# -r means, show the remote url instead of the directory.
shift
local show_dir=false show_repo=true
fi
if [[ $1 == -q ]]; then
# -q means, don't echo the separator line with the directory.
shift
local show_dir=false show_repo=false
fi
find . -name .git -type d -prune | while read d; do
local d=$(dirname "$d")
git -C "$d" rev-parse --verify -q "$test_branch" >& /dev/null || continue
if [[ $show_dir == true ]]; then
echo "---- $d ----"
fi
if [[ $show_repo == true ]]; then
echo "----" $(git -C "$d" config --get remote.origin.url) "----"
fi
if [[ $# == 1 && $1 == *' '* ]]; then
(cd "$d" && eval "$1")
else
(cd "$d" && "$@")
fi
done
}
gittree() {
# @ is in every repo, so this runs on all repos
gittreeif @ "$@"
}
Let’s say I want to summarize the changes between two tags. Here’s a
convenient alias to put in your ~/.gitconfig:
[alias]
relnotes = log --pretty='%h %ad %an: %s' --date=short --no-merges
The git command to show the changes between “old-commit” and “new-commit”
is:
git log new-commit ^old-commit
Putting it all together: to see the changes between juniper.2 and juniper.3
in all the repos that have Juniper branches, using “relnotes” to get the summary
style I like:
$ gittreeif \
open-release/juniper.master \
git relnotes open-release/juniper.3 ^open-release/juniper.2
---- ./ecommerce ----
ca9cddb4 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./devstack ----
10f02ca 2020-08-17 Zachary Trabookis: Remove `xqueue` as `DEFAULT_SERVICES` for
8ff8dd0 2020-08-17 Zachary Trabookis: Make additional adjustments to the docume
57455fe 2020-08-10 Zachary Trabookis: Add `xqueue` to default services to provi
3ca4c9d 2020-07-29 Zachary Trabookis: Make sure to pass in `DOCKER_COMPOSE_FILE
cef4aa2 2020-07-28 Zachary Trabookis: Updated `README` to include necessary inf
9415683 2020-07-27 Zachary Trabookis: Update `docker` commands to be `docker-co
67c7c9b 2020-08-16 morenol: Do not use openedx release for registrar and edx-mk
56312bc 2020-08-04 Guruprasad Lakshmi Narayanan: Remove duplicate section
34a46a3 2020-07-24 Guruprasad Lakshmi Narayanan: Remove the non-release service
---- ./xqueue ----
f004caa 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./edx-e2e-tests ----
---- ./edx-platform ----
d9e0ca5e70 2020-08-12 Ali-D-Akbar: This commit contains security fixes for the
c8421f66fc 2020-08-07 uzairr: Fix xss vulnerabilities in templates
47ab6af637 2020-08-06 Attiya Ishaque: [YONK-1759] Version bump of studio-fronte
8dd78619c9 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
b295389e96 2020-07-23 Zachary Trabookis: Set `SESSION_COOKIE_SAMESITE=Lax` for
91af099933 2020-07-23 uzairr: Fix xss in templates
0e45ecb743 2020-07-22 Ali-D-Akbar: Sustaining xss fixes This commit contains xs
3757f0d11e 2020-07-06 Florian Haas: Fix profile image URLs for image storage on
---- ./edx-analytics-pipeline ----
---- ./repo-tools/repo-tools ----
---- ./edx-notes-api ----
ad53edd 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./cs_comments_service ----
3079804 2020-08-19 Samuel Walladge: Bump codecov to latest version
---- ./course-discovery ----
e984f273 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./credentials ----
7a7aab55 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./src/edx-analytics-configuration ----
---- ./src/edx-documentation ----
---- ./src/configuration ----
05bb4edcf 2020-08-24 Feanil Patel: Improve sandboxing. (#5953) (#5960)
860994c0d 2020-08-21 Feanil Patel: Timmc/codejail improvements (#5956)
---- ./src/enterprise-catalog ----
f886da6 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./src/blockstore ----
---- ./src/edx-analytics-data-api ----
64b4c7f 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./src/frontend-app-publisher ----
---- ./src/edx-app-android ----
---- ./src/notifier ----
---- ./src/edx-analytics-dashboard ----
b8dfa559 2020-08-05 Ned Batchelder: Upgrade Django to 2.2.15
---- ./src/frontend-app-support-tools ----
---- ./src/edx-app-ios ----
---- ./src/edx-demo-course ----
---- ./src/ecommerce-worker ----
---- ./src/frontend-app-learning ----
---- ./src/edx-certificates ----
---- ./src/frontend-app-profile ----
---- ./src/license-manager ----
85003a6 2020-08-05 Ned Batchelder: Upgrade to Django 2.2.15
---- ./src/testeng-ci ----
---- ./src/frontend-app-gradebook ----
---- ./src/edx-developer-docs ----
---- ./src/frontend-app-account ----
This is how I do it. There are probably other tools to do the same job.
Maybe someone will point them out... :)
Enes Başpınar has translated one of my popular pages into Turkish:
Değişken Deyince Ne Anlamalı?
is his translation of my Facts and myths about Python names and values.
Google Translate tells me the Turkish title means, “What Should It Understand When You Say Variables?,”
which I guess is better translated as, “What Do We Mean When We Say Variables?”
It’s flattering that a piece is liked enough for someone to translate it.
The only previous page that was translated was Cog,
into Russian (twice!).
If you want to translate something on this site, let me know.
I’ve written a tool for managing changelog files, called
scriv. It focuses on a simple
workflow, but with lots of flexibility.
I’ve long felt that it’s enormously beneficial for engineers to write about
what they do, not only so that other people can understand it, but to help the
engineers themselves understand it. Writing about a thing gives you another
perspective on it, your own code included.
The philosophy behind scriv, and a quick list of other similar tools, is on the
Philosophy
page in the docs.
Scriv only does a few things now, but I’m interested to hear about other
changelog workflows that could use better tooling.
I threw together a Spotify API program called
song-basket. I have a few
large themed playlists (for example, Instrumental Funk). This app is to help me
add songs to them. I can choose a playlist (the basket), and then as I surf
around Spotify, it lets me add the current song to the basket with one click.
It also shows me whether the current song is already in the basket or not, which
they often are. If the song is already in the basket, I don’t have to think
about whether to add it, and I don’t have to deal with the annoying “Add
duplicate?” question.
This started as an
example
in the Tekore docs, and I hacked at it until it did what I wanted. A lot of
it is wrong: no templating, incorrect HTML, a stateful web application, horrid
styling, and so on. It doesn’t matter, it’s a quick app to do what I need. If
I want, I can polish it later.
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