string-kit 0.1.0a4

Library of string functions and formatters

Description

Provides advanced string utilities and a powerful Formatter.

This is a development version, and while it has been thoroughly tested, it will be battle-tested in a live project and updated as needed.

PowerFormatter

PowerFormatter is a drop-in replacement of str.Formatter and supports the same syntax and more.

PowerFormatter adds the following features:

• virtual fields now, uuid1, uuid4, uuid5 (no key is required in the format parameters, however if present, they take precedence); many more coming up.

• user-defined virtual fields can be added through field_default init parm.

• can send namespaces where format field values are searched through namespaces init parm.

• !capitalize, !lower, !lstrip, !rstrip, !slug, !strip, !title, upper; many more coming up.

• user-defined convertors can be added through convertors init parm.

• chained conversions and format specifications in any order: {field!slug:.10s!upper}.

• user-configurable silence_missing_fields, if set True, will suppress IndexError and KeyError and will quietly replace with empty string.

• user-configurable characters to identify fields (default {}), convertors (default !) and format specifiers (default :).

A simple example:

import random
from string_kit import PowerFormatter

my_field_defaults = {
    "greeting": "Hello",
    "password": lambda: random.choice(["lI0n", "rAbb1t", "tig3R"]) \
                        + str(random.randint(100, 999)),
}

my_weather = "Sunny and Wet"

my_convertors = {
    "s2d": lambda s: s.replace(" ", "-")
}

pf = PowerFormatter(
    silence_missing_fields=True,
    field_defaults=my_field_defaults,  # optional, dict with str or callable values
    convertors=my_convertors,          # optional, dict with callable values
    field_namespaces=[locals()],       # optional, namespaces to search for field names
)

print(pf.format("{greeting!upper} {fname!s2d}, this is your random password:"
                " '{password}'.", fname="Charlie Brown"))
# "HELLO Charlie-Brown, this is your random password: 'rAbb1t530'."

print(pf.format("Today is a {my_weather:.5!lower} day.{inexistent!lstrip}"))
# "Today is a sunny day."

Some TODO Ideas

• somehow send static parameters to convertors in format string, e.g. replace convertor with field-level replace string, i.e. {field:!replace(x,y)}`

• add snake_case, kebab-case, PascalCase, camelCase as built-in convertors

• add sqids convertor with parameters (strings allowed, length) passed as static values