Posts

Posted on

Format Percentage for Display in JavaScript

Input Output
0.12 12%
0.0012345 0.12%
0.0 0

2 significant digits but locale-sensitive, strip meaningless trailing zeroes and decimal dividers.

const formatPercentage = function (value) {
    return new Intl.NumberFormat(
        undefined, // use browser locale
        // Choose the options that get us closest to our desired style – a percentage that tells you enough to be useful but no unnecessary decimal places or trailing zeroes.
        {
            style: "percent", // Treat decimals as percentages, multiplying by 100 and adding a % sign.
            minimumSignificantDigits: 2,
            maximumSignificantDigits: 2
        }
    )
        .format(value)
        // \D here is the locale-agnostic decimals separator.
        .replace(/(\D[0-9]*?)0+%$/, "$1%") // Get rid of trailing zeroes after the decimal separator.
        .replace(/\D%/, "%") // Clean up the scenario where we got rid of everything after the decimal separator and now have something like "4.%.
        .replace(/^0%$/, "0"); // Replace literal "0%" with "0" as zero is unitless.
};
Posted on

Python Types for Union of String Literal and Other Type

I wanted to add a single special value to another type for a union type, something like this:

from typing import Literal
                                                                            
UNMEASURED = "unmeasured"                                                    
Unmeasured = Literal[UNMEASURED]
Resource = int | Unmeasured

notes: dict[Resource, str] = {1: "foo", 2: "bar", 3: "baz", UNMEASURED: "quux"}
resources = [1, 2, 3] + [UNMEASURED]
for resource in resources:
    print(notes[resource])

This works, but mypy complains: ‘error: Parameter 1 of Literal[…] is invalid [valid-type]’. So to make this pass mypy typechecking you have to repeat “unmeasured” as a literal. Even if you do that:

from typing import Literal

UNMEASURED = "unmeasured"
Unmeasured = Literal["unmeasured"]
Resource = int | Unmeasured

notes: dict[Resource, str] = {1: "foo", 2: "bar", 3: "baz", UNMEASURED: "quux"}
resources = [1, 2, 3] + [UNMEASURED]
for resource in resources:
    print(notes[resource])

mypy will complain: ‘Dict entry 3 has incompatible type “str”: “str”; expected “int | Literal[‘unmeasured’]”: “str” [dict-item]’ and also ‘Invalid index type “str | int” for “dict[int | Literal[‘unmeasured’], str]”; expected type “int | Literal[‘unmeasured’]” [index]’

Eventually I came up with:

from enum import Enum
from typing import Literal

class Aspect(Enum):
    UNMEASURED = "unmeasured"

Resource = int | Aspect

notes: dict[Resource, str] = {1: "foo", 2: "bar", 3: "baz", Aspect.UNMEASURED: "quux"}
resources = [1, 2, 3] + [Aspect.UNMEASURED]
for resource in resources:
    print(notes[resource])

which both produces the same result, and passes the typechecker. I don’t love the weird Enum hanging out on its own but it does at least put the magic string in one place only and pass. I wonder what would be better.

Posted on

Remember the Milk Alfred Workflow

This uses rtm-cli which you can install with npm.

query=$1
logfile="/Users/bakert/u/scratch/rtm.log"
rtm=/opt/homebrew/bin/rtm
max_lines=1000

# Log the query
echo "[$(date)] $query" >> "$logfile"

# Ensure the logfile does not grow beyond $max_lines
tail -n $max_lines "$logfile" > "$logfile.tmp" && mv "$logfile.tmp" "$logfile"

# Send the task to Remember the Milk
"$rtm" add $query

if [ $? -ne 0 ]; then
  echo "SOMETHING WENT WRONG! Please check that rtm-cli is installed: npm install -g rtm-cli"
else
  echo "[Added] $query"
fi
Posted on

Gmail Conversations Archiving Has Gotten Worse

You can search for emails in Gmail, “Select All” and Gmail will prompt you, “do you want to select all conversations that match this search?” rather than just the 100 you can see. Then if you do something like use the Archive keyboard shortcut it says “do you want to apply this to all conversations selected?” Previously this was instant. Now it says, “We archived some conversations. We’ll do the same for any remaining conversations in a few minutes. This might take longer, depending on how many conversations are selected.” And if you go back to your Inbox they’re still there. A real downgrade!
Posted on

assertRaises in table-driven tests

This is what I want to do but it fails passing None to assertRaises:

tests = [
   (0, None),
   (1, None),
   (-1, TooFewException),
   (99, None),
   (100, TooManyException),
]
for n, exc in tests:
    with self.assertRaises(exc):
        results = my_code(n)
        assert len(results) == n

Here’s a version of assertRaises that will let you do that:

    def assert_raises(self, exception: Type[Exception]):
        if exception:
            return self.assertRaises(exception)
        return contextlib.nullcontext()
Posted on

Line Count

Number of lines in a (python + js) codebase:

#!/bin/zsh

# This script counts the number of non-blank lines of code in a directory and its subdirectories
# for Python and JavaScript code only

# Set the directory to search for code files
dir='.'

# Count the number of non-blank lines of code for Python and JavaScript files
num_lines=$(find "$dir" -type f \( -name '*.py' -or -name '*.js' \) -not -path '*venv*' -not -path '*node_modules*' -exec grep -he '^[^[:space:]]' {} + | awk 'NF{count++} END{print count}')

echo "Number of non-blank lines of code: $num_lines"

Number of lines per-file in a (python + js) codebase:

#!/bin/zsh

# This script counts the number of non-blank lines of code in a directory and its subdirectories
# for Python and JavaScript code only

# Set the directory to search for code files
dir='.'

# Count the number of non-blank lines of code for Python and JavaScript files
num_lines=$(find "$dir" -type f \( -name '*.py' -or -name '*.js' \) -not -path '*venv*' -print0 | xargs -0 grep -cve '^[[:space:]]*
)

echo "Number of non-blank lines of code: $num_lines"