Strings¶

arvel provides Str, a collection of string-manipulation functions, and a fluent Stringable wrapper for chaining them. Most helpers exist because Python's str lacks the higher-level, framework-flavored operations (case conversion, inflection, slugs) you reach for constantly in a web app.

Introduction¶

There are two styles. Str is a set of static methods for one-off transformations; Str.of() returns a Stringable you can chain fluently and unwrap at the end.

from arvel.support import Str

Str.slug("Arvel Framework")        # "arvel-framework"
Str.of("  Hello  ").trim().lower().slug()   # a chainable Stringable

Available methods¶

Case & inflection¶

Str.camel("foo_bar")        # "fooBar"
Str.studly("foo_bar")       # "FooBar"
Str.snake("fooBar")         # "foo_bar"
Str.kebab("fooBar")         # "foo-bar"
Str.title("a nice day")     # "A Nice Day"
Str.headline("some_method") # "Some Method"
Str.plural("post")          # "posts"
Str.singular("posts")       # "post"

Slugs & identifiers¶

Str.slug("Hello World!", separator="-")   # "hello-world"
Str.ulid()                                # a sortable unique id
Str.is_uuid(value)                        # True for a well-formed UUID

Search & extraction¶

Str.contains("haystack", "st")     # True
Str.starts_with("arvel", "arv")    # True
Str.ends_with("arvel", "vel")      # True
Str.after("[email protected]", "@")          # "b.com"
Str.before("[email protected]", "@")         # "a"
Str.after_last("a/b/c", "/")       # "c"
Str.before_last("a/b/c", "/")      # "a/b"
Str.is_("admin/*", "admin/users")  # glob match → True

Trimming & masking¶

Str.limit("A long sentence", 6)     # "A long..."
Str.mask("4242424242424242", "*", index=0, length=12)   # "************4242"

Fluent strings¶

Str.of() wraps a value so every operation returns another Stringable, letting you chain — then .to_str() (or str()) unwraps:

name = (
    Str.of("  Jane DOE  ")
       .trim()
       .title()          # "Jane Doe"
       .slug()           # "jane-doe"
       .to_str()
)

Stringable exposes the full toolbox — case (upper/lower/ucfirst/camel/snake/slug…), extraction (after/before/between/substr/take), editing (replace/replace_first/remove/ swap/mask), inflection (plural/singular/headline), and trimming (limit/words/excerpt/ word_wrap) — each returning a new Stringable so nothing mutates in place.