ferd.ca – Home Alone: A Post Incident Review

It’s so many things in one: a movie review, an intro to “post incident reviews,” a lesson into which kinds of precautions work and which don’t, and a reminder that things can still go wrong even when well prepped.

Ad Fontes Media rates media outlets according to their bias and reliability. 1) factual reporting has very slight left-leaning bias (see also “Facts Have a Well-Known Liberal Bias”) and consequently 2) it doesn’t seem to be possible to be reliable and biased at the same time.

In Hard to discover tips and apps for making macOS pleasant Tristan Hume says:

Chrome and Firefox have much better sounding audio resampling for watching videos on 1.5x or 2x speed. This is the only reason I don’t use Safari.

I just tried it and oh my is this true!

2020 Holiday Newsletter

For the past 4 years, just before the holidays, I’ve sent a newsletter to my colleagues about all the things I’ve read, watched, listened to, cooked, or ate in the last year. This is the 2020 edition.

The Christopher Alexander idea patch

Where I’m from, there are so many blueberries that people from that region are called bleuets. (The tourist info phone number is 1-877-BLEUETS (253-8387). You should go and visit.) When you go out to pick them (the blueberries, not the people) and you hit a patch with tons of them, we say “I found une talle!” That’s how it felt getting into Christopher Alexander’s ideas.

You might know of Alexander without realizing it. He’s considered as the father of the idea of design patterns, which were heavily inspired by his book architecture book A Pattern Language. Patterns are part of a larger process to solve design problems, from problem definitions, to solutions, to the evaluation of how good the solution is. It’s that larger process that I found interesting. He named the parts of the process context, form, and fit. In brief, the context is the problem to be solved together with its constraints. It’s totally independent of the solution. The form is the solution. It has a shape that fits the context more of less well. Once I had these words in my mind, I started seeing them everywhere.

Clay Christiensen’s Jobs-to-be-Done framework (from Competing Against Luck) is a way of defining product opportunities (jobs) as a context that can be fulfilled in many different ways. To get an idea of what that means, watch him telling the story of the job of a milkshake and how milkshakes compete with bananas, donuts, and bagels, and not with ice cream.

In Demand-Side Sales, Bob Moesta (who did the milkshake research) talks about selling from the buyer’s perspective, from their struggles, from their context. In contrast to selling from the supply-side, which talks about features and form words. I highly recommend this book.

On the programming side, unit testing has morphed into form testing, whereas the original intent was context testing. Behavior-driven development tried to get that spirit back. What I heard Ian Cooper say in his TDD, Where Did It All Go Wrong talk was “Write context tests.”

Basecamp’s Shape Up is basically Alexander’s ideas applied to product development and management. It makes a clear distinction between shaping (defining the problem and the context) and doing the work (creating a form). Which in turns allows a new dimension of diagnosis when a project fails: was the project badly shaped or is it that the execution failed and form was a bad fit?

Ryan Singer, head of strategy at Basecamp, did a great intro to Alexander’s work this summer.

The Best Writing

Losing the War by Lee Sandlin is the best writing I read this year (and I read it on January 1, 2020). It’s an incredible essay on war (the Second World One), and memories. I found the “flow” to be exemplary with plenty of historical context and commentary. Well worth the time.

programming == cooking

I used to tell students that I was “teaching them how to fish.” But after reading Robin Sloan’s Home Cooked App, I’ve started telling people I’m teaching them how to cook. It’s a much richer analogy.

If you don’t know how to cook, you eat pre-packaged meals or you eat out (or you live with your mom forever). But there are tons of reasons to want to learn how to cook and tons of things to do once you’ve learned how. You can cook for health reasons, to please friends, to create the perfect version of something, as a creative output, because you’re picky, to make food you want to eat, because it’s fun. You can specialize and become a baker, or open a taco truck, or start a family restaurant, or run a fine-dining restaurant. You can teach others how to cook. In the end, you can still go out and eat if you want, you have a choice. There are so many reasons to learn to cook.

If you don’t know how to program (or how to reason about programming) you use apps you bought and hire consultants. But there are tons of reasons to want to learn how to program and tons of things to do once you’ve learned how. You can create little scripts to rename files, write notebooks to make custom analyzes, write an app to enable friends and colleagues to explore data like you can, write your own text editor (!) because vim is holding you back, because it’s fun. You can specialize and build deep learning models, or design data management systems, or build custom web apps, or start a scientific software development consultancy. You can teach others how to program. In the end, you can still hire consultants if you want, you have a choice. There are so many reasons to learn to program.


The Glamorous Toolkit is an impressive “moldable development environment”. I’d describe it as a strange hybrid between a notebook editor and an IDE. Any objects can have a rich and interactive representations, which is not new (to us), but the cool part is that it’s easy to dynamically add new rich representations to the development environment. Watch this talk by Tudor Gîrba to get a taste of what’s possible.

Simon Willison’s (co-creator of Django) Datasette is an impressive project to “explore and publish data”. It relies heavily on sqlite. I look forward to playing with it some more over the holidays. He’s done super cool things with it, including finding the best photo of a pelican according to Apple Photos, and building a regex search engine across a collection of Github repos using ripgrep.


I started many books this year, but didn’t finish that many:

  • Thinking in Systems by Donella Meadows is a short introduction to “systems thinking,” their components (stocks, flows, feedback loops), common system configurations, common pitfalls/opportunities of those configurations, and leverage points to intervene in those systems. I had so many “Ah ha!” moments. Many about things I “knew” but hadn’t realized the consequences of. Like how “systems with similar feedback structures produce similar dynamic behaviors, even if the outward appearance of these systems is completely dissimilar.” For example, a population system (controlled by births and deaths) has a similar configuration as an economic capital system (controlled by investment and depreciation). Reading this book, it was so easy to think “Here’s a silver bullet!” but then she totally called me out on it:

    People who are raised in the industrial world and who get enthused about systems thinking are likely to make a terrible mistake. They are likely to assume that here, in systems analysis, in interconnection and complication, in the power of the computer, here at last, is the key to prediction and control. This mistake is likely because the mind-set of the industrial world assumes that there is a key to prediction and control.

  • Elements of Typographic Style by Robert Bringhurst. Yes it’s a typography book, but it may also be the funniest thing I read all year. Bonus: the book itself is a beautiful object.

  • Lab Girl by Hope Jahren is a wonderful memoir of a “life in science.” She’s a good storyteller, telling a good story, about how the path to success in academia can be wild.

But I read a lot of good articles:

TYIL (This Year I Learned)

The Ouarzazate Solar Power Station melts salt by concentrating the power of 7400 parabolic mirrors towards a central tower. The molten salt is then used to superheat water and power steam-powered generators.

It’s possible to tell one’s position in the sea based on wave patterns. The 2016 NYT piece by Kim Tingley, The Secrets of the Wave Pilots, is an impressive testament of what our brains can perceive using our full bodies as sensors. See also these beautiful Marshall Islands navigation charts, and the Eagle Eyes Radiolab story about the vest David Eagleman is building to help deaf people hear.

Some Nice Pandemic things


I started making pizza just after the pandemic started. I can’t wait for it to be over to organize pizza parties. My source of knowledge is Ken Forkish’s Elements of Pizza. Using tipo 00 flour is worth it. So is a baking steel/stone.

Kenji Alt Lopez’s Serious Eats episode on emulsions has a really compelling demonstration of why you should put a surfactant in your emulsions. Now I put a little dollop of mustard in all my vinaigrettes.


My friend Matt shared some bardcore videos by Hildegard von Blingin’ earlier this year. Here’s Somebody That I Used To Know (Bardcore/Medieval Style Cover with Vocals). Bardcore is medieval renditions of pop songs. Obviously. So… the name Hildegard von Blingin’, is a reference to Hildegard von Bingen, an 11th century badass abbess, composer, and scientist (among others). In the early 2000, my mom gave me a CD by Garmarna, a Swedish band that does… electro-folk renditions of her 11th-century music. Hildegard von Blingin' = 1/Garmarna! Here’s one song and here’s the whole Garmarna album.

According to Spotify and Last.fm, I’ve listened to 1,700+ different artists this year, 600 of which were new to me. I won’t give you the whole list, don’t worry. Although I do have a playlist of every album I liked in 2020 and one of only the best songs I listened to in 2020.

Here are my favorite albums released in 2020, in no particular order.

Here’s more great music I discovered this year but that wasn’t made this year.

I somehow ended up listening to a lot of Japanese indie music (for a lack of better term).


  • The Newsroom by Aaon Sorkin is the best series I watched this year. Great characters, surprisingly funny, great storylines and overall arc.
  • Ted Lasso is a close second.
  • Crictor makes wonderful short, really short, videos. Do watch Popcorn (15 sec) and Hanabi (fireworks in Japanese, a big 45 sec).
  • The Last Dance (Netflix), on Michael Jordan’s career was a riveting watch. I vividly remember the 1997 Utah game where Jordan “had the flu” and still scored 38 points. At the time, my English wasn’t so great and I remembered being puzzled by the fact that the announcer said Jordan had “the flu” (which in québécois basically means diarrhea). Well, I learned that he probably did have the runs! He didn’t have the flu, he had food poisoning from a bad pizza probably given to him by disgruntled Jazz fans. Take that, Jazz!
  • The Good Place (Netflix) is an unlikely great show about… philosophy. My favorite character is Jason Mendoza. I’d watch it again.
  • The West Wing: got me into Sorkin. I shed a tear during 5 of the first 5 episodes.
  • I was going to say that The Magicians was funny, smart, emotional, with a great cast, and a fantastic ending. But as I write this, I learned there’s a 5th season I didn’t know existed. So take my “great ending” comment with a grain of salt.

I just finished reading Thinking in Systems: A Primer by Donella H. Meadows. I believe sometimes one was to be “ready” to read a book. I must have been ready for this one because I had more “Holy sh!t” moments than any other book I’ve read in years.📚

Austin, TX, 8:15. Morning walk around the neighborhood. There are many good Halloween decorations, but this one is particularly entertaining. #adayinthelife

Given what happened to the other saguaro, it makes me fear that this one will fall too.

I took this photo of a saguaro a month ago. It had been partially burnt during the fires that happened north of Phoenix earlier this summer. This weekend I realized it had fallen. According to Wikipedia, saguaros grow their first arm around 75–100 years of age. 👋🌵😔

Custom URL Handler for Files With Unique IDs

Yesterday I read a series of posts on custom URL scheme handlers on the Zettelkasten forums. The handler registers itself to open links like zettel://202006061337, where the number is the unique ID of a zettel (here it’s a timestamp). I’m not sure everyone realized the magnitude of what that means.

Combining a custom URL with a unique ID means notes and links can become entirely independent from your apps. Only the handler needs to know about the apps you’re using.

That alone is very nice, but then I thought: URLs can have query parameters… That means I can have URLs like zettel://202006061337&edit that open in my text editor of choice: TextMate, BBEdit, WriteRoom, FoldingText, etc. Or zettel://202006061337&preview to open in Marked. Or I could even pick the app interactively with zettel://202006061337&pick.

Handling the ID alone is pretty easy since the common Zettelkasten-like apps respond to a URL scheme to search and open files. The Archive uses thearchive://match/ID, nvUltra uses x-nvultra://find/ID, and nvAlt uses nvalt://find/ID.

But how to open in a text editor or in Marked given only the ID? With Spotlight. I used mdfind -name ID to find the file. This could be further refined with the -onlyin FOLDER option but I didn’t need it. Then it’s a matter of calling open -a Marked FILEPATH.

There’s also a zettel://create special case that will create a new zettel with the current time stamp (YYYYMMDDHHMM). It’s always done with the default Zettelkasten app because the script doesn’t know where to write the file but the app does.

I wrote the handler in Applecript because it’s the easiest way I know to create something that macOS considers an “app” and that can therefore handle URLs.

The full script is below. To use it:

  1. Open Script Editor and paste the code below in a new file.
  2. [Optional] Modify values in the Configuration section to pick a different URL prefix, default Zettelkasten app URL, editor, and previewer. You can add as many apps as you’d like in the appChoices array.
  3. Save as “Application”. You can save it anywhere. Make sure none of the boxes are checked.
  4. Register the app as a URL handler. You can do it with the SwiftDefaultApps Preference pane, or using the instructions provided by Christian Tietze in the forums:
    • Locate the application file you just created
    • Right-click the app, select “Show Package Contents”
    • Inside, open Contents/Info.plist with a text editor
    • Paste the following in a blank line right below the <dict> line. Replace zettel with the URL prefix you’ve chosen:
        <string>Zettel Link Opener</string>

Here’s the full script:

-- Zettel Link Opener
-- Created by Alexandre Chabot-Leclerc
-- Source: https://alexchabot.net/2020/06/06/custom-url-handler-for-zettels/
-- URL Handler for zettelkasten unique IDs, e.g., zettel://202006061017
-- Handles options after the ID to open different apps:
--    zettel://202006061017&edit to open is a text editor like TextMate
--    zettel://202006061017&preview to open in a preview app like Marked
--    zettel://202006061017&pick to open a menu of apps to pick from

-- URL prefix for your custom URL, e.g. zettel://ZETTEL_ID
property urlPrefix : "zettel"

-- Default URL to call to open a note with a given ID. The ID will be appended
property defaultZkAppUrl : "thearchive://match/"
--property defaultZkAppUrl : "nvalt://find/"
--property defaultZkAppUrl : "x-nvultra://find/"

-- URL to use to create a new zettle with the current timestamp YYYYMMDDHHMM
property urlForCreation : "thearchive://matchOrCreate/"
--property urlForCreation : "nvalt://make?txt="
--property urlForCreation : "x-nvultra://make?txt="

-- Apps to use for the different query parameters
property editApp : "FoldingText" -- App to used with "&edit" query parameter
property previewApp : "Marked" -- App to used with "&preview" query parameter 

-- List of app to display in the menu with with &pick query option
-- The apps will appear in the order defined here
property appChoices : {defaultZkAppUrl, editApp, previewApp, "TextMate"}
property defaultApp : {defaultZkAppUrl})

on splitText(theText, theDelimiter)
	set AppleScript's text item delimiters to theDelimiter
	set theTextItems to every text item of theText
	set AppleScript's text item delimiters to ""
	return theTextItems
end splitText

on removeUrlPrefix(original)
	-- Remove URL prefix so we're left with only the ID and the optional query parameter
	return do shell script "echo " & quoted form of original & " | sed 's;" & urlPrefix & "://;;'"
end removeUrlPrefix

on getIdAndOption(resouceAndQuery)
	-- Split the zettel ID and the optional parameter
	-- For example 202006061012&edit or 202006061012&preview
	set theItems to splitText(resouceAndQuery, "&")
	if length of theItems is 1 then
		-- Append an empty string if there's no option so this
		-- function always returns an array of 2 elements
		copy "" to the end of theItems
	end if
	return theItems
end getIdAndOption

on findFilepath(zk_id)
	-- Finds the filepath using Spotlight.
	-- It's easier than finding the proper filename given only the zettel ID
	return do shell script "mdfind -name " & zk_id
end findFilepath

on createZettel()
	set newZkId to do shell script "date +'%Y%m%d%H%M'"
	do shell script "open " & urlForCreation & newZkId
end createZettel

on openInChoosenApp(zkId, zkFilepath)
	--	From Simple List Handler by Patrick Welker <http://rocketink.net>
	-- Promp the use for the app to use
	set selectedApp to item 1 of (choose from list the appChoices with title "Available App" with prompt "Which app do you want to use?" default items defaultApp)
	if selectedApp is false then
		-- Exit prematurly if the user clicked Cancel
		error number -128
	end if
	-- Open the URL directly, or open by app name
	if selectedApp contains "://" then
		do shell script "open " & selectedApp & zkId
		do shell script "open -a " & selectedApp & " " & quoted form of zkFilepath
	end if
end openInChoosenApp

on open location thisURL
	set resouceAndQuery to removeUrlPrefix(thisURL)
	set idAndOption to getIdAndOption(resouceAndQuery)
	set zkId to item 1 of idAndOption
	if zkId is "create" then
	end if
	set zkFilepath to findFilepath(zkId)
	if item 2 of idAndOption is "edit" then
		do shell script "open -a " & editApp & " " & quoted form of zkFilepath
		-- Exit the script immediately so we don't also open in the default app
	else if item 2 of idAndOption is "preview" then
		do shell script "open -a " & previewApp & " " & quoted form of zkFilepath
		-- Exit the script immediately so we don't also open in the default app(
	else if item 2 of idAndOption is "pick" then
		openInChoosenApp(zkId, zkFilepath)
	end if
	-- Fall back to the default handler if there was no option
	-- or the option was invalid
	do shell script "open " & defaultZkAppUrl & zkId
end open location

What does %matplotlib do in IPython?

TLDR; Use %matplotlib if you want interactive plotting with matplotlib. If you’re only interested in the GUI’s event loop, %gui <backend> is sufficient.

I never really understood the difference between %gui and %matplotlib in IPython. One of my colleagues at Enthought once told me that at some point in his career, he more or less stopped reading documentation and instead went straight to the code. That’s what I did here. But let’s do a bit of history first.

In the “beginning”, there was pylab. It (still) is a module of matplotlib and was a flag to IPython designed to facilitate the adoption of Python as a numerical computing language by providing a MATLAB-like syntax.1 The reference was so explicit that before being renamed to pylab on Dec 9, 2004, the module was called matplotlib.matlab. IPython adopted the rename on the same day.2 With the ‑‑pylab flag or the %pylab magic function, IPython would set up matplotlib for interactive plotting and executed a number of imports from IPython, NumPy and matplotlib. Even thought it helped a few people transition to Python (including myself), it turned out to be a pretty bad idea from a usability point of view. Matthias Bussonnier wrote up a good list of the many things that are wrong with it in “No Pylab Thanks.”

For the 1.0.0 release of IPython in August 2013, all mentions of %pylab were removed from the examples (in a July 18, 2013 commit) and were replaced by calls to the %matplotlib magic function, which only enables interactive plotting but does not perform any imports. The %matplotlib function had already been introduced in a 2013 refactoring to separate the interatice plotting from the imports. The %gui magic command had already been introduced in 2009 by Brian Granger to “manage the events loops” (hint hint).

Now we know that the (my) confusion with %gui and %matplotlib started in 2013.

This analysis refers to IPython 7.8.0 and ipykernel 5.1.2.

Our entry point will be the %matplotlib magic command. Its source code is in the IPython.core.pylab.py file. The essential call is to shell.enable_matplotlib(gui), which is itself implemented in IPython.core.interactiveshell.InteractiveShell, and does five things:

  1. Select the “backend” given the choice of GUI event loop. This is done by calling IPython.core.pylabtools.find_gui_and_backend(gui). It encapsulates the logic to go from a GUI name, like "qt5" or "tk", to a backend name, like "Qt5Agg" and "TkAgg".
  2. Activate matplotlib for interactive use by calling IPython.core.pylabtools.activate_matplotlib(backend), which:
    1. Activates the interactive mode with matplotlib.interactive(True);
    2. Switches to the new backend with matplotlib.pyplot.switch_backend(backend);
    3. Replaces the matplotlib.pyplot.draw_if_interactive method with the same method, but wrapped by a flag_calls decorator, which adds a called flag to the method. That flag will be used by the new %run runner that’s introduced below at point #5;
  3. Configure inline figure support by calling IPython.core.pylabtools.configure_inline_support(shell, backend). This is where some very interesting stuff happens. It first checks that InlineBackend is actually importable from ipykernel.pylab.backend_inline, otherwise it returns immediately. But if it’s importable and the backend is "inline", it:
    1. Imports the ipykernel.pylab.backend_inline.flush_figures function, and register it as a callback for the "post_execute" event of the shell. As we’ll see later, callbacks for "post_execute" are called after executing every cell;
    2. If the backend was not "inline", it’ll unregister the flush_figures callback;
  4. Enable the GUI by calling shell.enable_gui(gui). This method is not implemented in the IPython.core.interactiveshell.InteractiveShell base class, but rather in IPython.terminal.interactiveshell.TerminalInteractiveShell. If a gui as specified, it gets the name of the active_eventloop and its corresponding inputhook function using IPython.terminal.pt_intputhooks.get_inputhook_name_and_func(gui). The active_eventloop is just a string, such as 'qt', but the inputhook is more interesting. It’s the function to call to start that GUI toolkit’s event loop. Let’s dig further into get_inputhook_name_and_func(gui). That function checks a few things, but it essentially:
    1. Imports the correct inputhook function for the chosen GUI by importing it from IPython.terminal.pt_intputhooks.<gui_mod>. For example, the Qt inputhook is imported from IPython.terminal.pt_intputhooks.qt. Later on, when inputhook is executed for Qt, it will:
      1. Create a QCoreApplication;
      2. Create a QEventLoop for that application;
      3. Execute the event loop and register the right events to make sure the loop is shut down properly. The exact operations to start and stop the loop are slightly different for other GUI toolkits, like tk, wx, or osx, but they all essentially do the same thing. At this point we’re ready to go back up the stack to enable_matplotlib in %matplotlib;
  5. Replace IPython’s default_runner with the one defined in IPython.core.pylabtools.mpl_runner. The default_runner is the function that executes code when using the %run magic. The mpl_runner:
    1. Saves the matplotlib.interactive state, and disables it;
    2. Executes the file;
    3. Restores the interactive state;
    4. Makes the rendering call, if the user asked for it, by checking the plt.draw_if_interactive.called flag that was introduced at point #1.3 above.

As for the other magic, %gui, it only executes a subset of what %matplotlib does. It only calls shell.enable_gui(gui), which is point #4 above. This means that if your application requires interaction with a GUI’s event loop, but doesn’t require matplotlib, then it’s sufficient to use %gui. For example, if you’re writing applications using TraitsUI or PyQt.

The Effect of Calling %gui and %matplotlib

Let’s start with the “simplest” one, %gui. If you execute it in a fresh IPython session, it’ll only start the event loop. On macOS, the obvious effect of this is to start the Rocket icon.

Animation of the Python rocket icon starting because of a call to `%gui`.

At that point, if you import matplotlib and call plt.plot(), no figure will appear unless you either call plt.show() afterwards, or manually enable interactive mode with plt.interactive(True).

On the other hand, if you start your session by calling %matplotlib, it’ll start the Rocket and activate matplotlib’s interactive mode. This way, if you call plt.plot(), your figure will show up immediately and your session will not be blocked.

Using %run

If you call %run my_script.py after calling %matplotlib, my_script.py will be executed with the mpl_runner introduced above at point #5.

Executing a Jupyter Notebok Cell When Using the "inline" Backend

In the terminal the IPython.terminal.interactiveshell.TerminalInteractiveShell.interact() method is where all the fun stuff happens. It prompts you for code, checks if you want to exit, and then executes the cell with InteractiveShell.run_cell(code) and then trigger the "post_execute" event for which we’ve registered the ipykernel.pylab.backend_inline.flush_figures callback. As you might have noticed, the flush_figures function comes from ipykernel, and not from IPython. It tries to return all the figures produced by the cell as PNG of SVG, displays them on screen using IPython’s display function, and then closes all the figures, so matplotlib doesn’t end up littered will all the figures we’ve ever plotted.


To sum it up, use %matplotlib if you want interactive plotting with matplotlib. If you’re only interested in the GUI’s event loop, %gui <backend> is sufficient._ Although as far as I understand, there’s nothing very wrong with using %matplotlib all the time.

  1. Basically, no namespaces, and direct access to functions like plot, figure, subplot, etc. [return]
  2. The earliest commit I found for the IPyhon project was on July 6, 2005 by Fernando Perez, 7 months after the name change. Its Git hash is 6f629fcc23ba63342548f61cc7307eeef4f55799. But the earliest mention is an August 2004 entry in the ChangeLog: “ipythonrc-pylab: Add matplotlib support,” which is before the offical rename in matplotlib. [return]

Manually Merging Day One Journals

My first Day One entry is from January 24, 2012. I used it often to take note about what I was doing during my PhD with the #wwid tag (what was I doing, an idea from Brett Terpstra, I think), and sometimes to clarify some thoughts.

When Day One went The Way of the Subscription, I didn’t bother too much because Dropbox sync still worked. Until it didn’t. I somehow didn’t realized it and kept adding entries to both the iOS and the macOS versions. Not good. It’s been on my to do list for a while to find a way to merge the two journals. I could probably subscribe to the Day One sync service and have it figure out the merging but I didn’t want to subscribe just for that.

I learned somewhere that Day One 2 could export journals as a folder of photos and a JSON file. I figure I could probably write a script to do the merging. So I downloaded Day One 2 on my iPhone and Mac, imported my Day One Classic journals, exported them as JSON to a folder on my Mac, and unzipped them. I also created a merged/ folder where to put the merged journal. The hierarchy looks like this:

$ tree -L 2
├── Journal-JSON-ios/
│   ├── Journal.json
│   └── photos/
├── Journal-JSON-ios.zip
├── Journal-JSON-mac/
│   ├── Journal.json
│   └── photos/
├── Journal-JSON-mac.zip
├── merge_journals.py
└── merged/

I first copied the photo folder from Journal-JSON-ios/ to merged/ and the photos from Journal-JSON-mac/photos/. I was pretty confident that I would end up with the union of all the photos because Day One uses UUIDs to identify each photo. The -n option to cp prevents overwriting files.

$ cp -r Journal-JSON-ios/photos merged/
$ cp -n Journal-JSON-mac/photos merged/photos/

I then ran the merge_journals.py script (below) to do a similar merge of the entries, based on the UUIDs. The merging happens by building a dictionary with UUID of each entry as the key and the entry itself as the value. It’s two loops over the iOS and the macOS entries. Entries with the same UUID should have the same contents, unless I’ve edited some metadata on one platform but not the other. I’m not too worried about that.

The output dictionary will be written to the Journal.json file. The entries are sorted chronologically because that’s how it was in the exported journal files, but I doubt it matters.

The output dictionary is written to disk without enforcing the conversion to ASCII since the exported journals are encoded using UTF-8. The indent is there to make the output more readable and diff-able with the exported journals.

import json

with open('./Journal-JSON-ios/Journal.json') as f:
    ios = json.load(f)
with open('./Journal-JSON-mac/Journal.json') as f:
    mac = json.load(f)

# Extract and merge UUIDs
uniques = {entry['uuid']: entry for entry in ios['entries']}
for entry in mac['entries']:
    uniques[entry['uuid']] = entry

# Create the output JSON data structure
output = {}
output['metadata'] = mac['metadata']
output['entries'] = list(uniques.values())
# I'm not sure it matters, but Day One usually exports the entries
# in chronological order
output['entries'].sort(key=lambda e: e['creationDate'])

# ensure_ascii print unicode characters as-is.
with open('merged/Journal.json', 'w', encoding='utf-8') as f:
    json.dump(output, f, indent=True, ensure_ascii=False)

The last step is to zip the journal and photos together, which tripped me up a few times. The Journal.json and the photos/ folder must be at the top level of the archive, so I zip the file from within the merged/ folder and then move it back up one level.

$ cd merged
$ zip -r merged.zip *
$ mv merged.zip ..

I could then import merged.zip in Day One, which created a new Journal, and delete the old one.

I guess I could somewhat automate this to roll my own, DIY, sync between versions of Day One, but I’d rather pay them money once I decide to use Day One frequently again. Still, I really appreciate that the Day One developers picked formats that could be manipulated so easily.

By far the best thing I’ve seen at Disney World so far.

Bread #2.

The Modern, Fort Worth.

The weight of the world.

By Giacometti.

There’s sometimes action out of my window.

Got a new room, with view on the East River. Much upgrade.

Wind tunnel model. Most beautiful item at the Musée des Confluence.

Anna going a bit overboard: crunchy speculoos, crème fraîche, and… maple syrup.

Party prep (Marshmallows + Jello powder)

Place des moulins, Marseille.