.ascii_letters: Str
.ascii_lowercase: Str
.ascii_uppercase: Str
.digits: Str
.hexdigits: Str
.octdigits: Str
.punctuation: Str
.printable: Str
.whitespace: Str

.capwords: (s: Str, sep := Str) -> Str

.Template: ClassType
.Template.
    template: Str
    __call__: (template: Str) -> .Template
    substitute: (self: .Template, mapping := {Str: Str}, **kws: Str) -> Str
    safe_substitute: (self: .Template, mapping := {Str: Str}, **kws: Str) -> Str
    is_valid: (self: .Template) -> Bool
    get_identifiers: (self: .Template) -> [Str; _]

FormatterIterator = 'formatteriterator': ClassType
FormatterIterator <: Iterable [Str; _]

.Formatter: ClassType
.Formatter <: InheritableType
.Formatter.
    __call__: () -> .Formatter
    format: (self: .Formatter, format_string: Str, *args: Obj, **kwargs: Obj) -> Str
    vformat: (self: .Formatter, format_string: Str, args: [Obj; _], kwargs: {Str: Obj}) -> Str
    parse: (self: .Formatter, format_string: Str) -> FormatterIterator
    get_field: |T, U|(self: .Formatter, field_name: Str, args: [T; _], kwargs: {Str: U}) -> (T or U, Str or Int)
    get_value: (|T|(self: .Formatter, key: Str, args: [Obj; _], kwargs: {Str: T}) -> T) \
        and (|T|(self: .Formatter, key: Nat, args: [T; _], kwargs: {Str: Obj}) -> T)