Text Processing

translit offers two ways to compose multiple transforms: the fluent Text builder for readability and one-off processing, and TextPipeline for high-throughput batch use.

Wrap a string in Text, chain methods, extract with .value or str(). Each method returns a new Text — immutable, like Python str.

from translit import Text

result = (Text("  Héllo   Straße  ")
    .normalize(form="NFC")
    .transliterate(lang="de")
    .fold_case()
    .collapse_whitespace()
    .value)
# => "hello strasse"

Ordering is explicit

Steps execute in the order you chain them. This gives full control — there is no hidden reordering.

# Strip accents first, then transliterate the remainder
Text("café").strip_accents().transliterate().value  # => "cafe"

# Transliterate first (accents handled by the transliteration table)
Text("café").transliterate().value                  # => "cafe"

Branching

Because each step returns a new Text, you can branch from a common base:

base = Text("Héllo Wörld").normalize(form="NFC")

ascii_version = base.transliterate().value          # => "Hello World"
lowered = base.fold_case().value                    # => "héllo wörld"
slug = base.transliterate().slugify().value         # => "hello-world"

Available transforms

All 8 standalone transform functions are available as chainable methods:

Method Description
.normalize(form) Unicode normalization (NFC, NFD, NFKC, NFKD)
.normalize_confusables() Replace homoglyphs with Latin equivalents
.strip_accents() Remove combining diacritical marks
.transliterate(lang=...) Unicode → ASCII transliteration
.fold_case() Unicode case folding (ß→ss, İ→i̇, etc.)
.collapse_whitespace() Normalize whitespace, strip control chars
.slugify(separator=...) URL-safe slug generation
.sanitize_filename() OS-safe filename sanitization

Predicates

Predicates return their native type and do not chain:

t = Text("hello мир")
t.is_mixed_script()   # => True
t.detect_scripts()    # => [Script.LATIN, Script.CYRILLIC]
t.is_ascii()          # => False

Text("café").transliterate().is_ascii()  # => True (check the transformed text)

Extracting the result

t = Text("café").transliterate()

t.value       # "cafe" — property access
str(t)        # "cafe" — str() conversion
len(t)        # 4
t == "cafe"   # True — compares with str directly

TextPipeline (batch processing)

TextPipeline is a pre-compiled, reusable processor. Configure once at construction, call repeatedly. Operations execute in a fixed optimal order regardless of how you specify them.

Use this when processing large datasets where the same transform chain applies to every item.

from translit import TextPipeline

pipe = TextPipeline(
    normalize="NFC",
    confusables=True,
    strip_accents=True,
    fold_case=True,
    collapse_whitespace=True,
)

# Call repeatedly — construction cost amortized
for text in large_dataset:
    cleaned = pipe(text)

Parameters

Parameter Type Default Description
normalize str \| None None Normalization form: "NFC", "NFD", "NFKC", "NFKD"
transliterate bool False Convert to ASCII via transliteration tables
lang str \| None None Language profile for transliteration. Use "auto" to detect from script.
confusables bool False Normalize confusable homoglyphs to Latin
strip_accents bool False Remove diacritical marks
fold_case bool False Unicode case folding
collapse_whitespace bool False Normalize whitespace to single spaces
strip_control bool \| None None Strip control characters. Defaults to True when collapse_whitespace=True, False otherwise. Can be used independently.
strip_zero_width bool \| None None Strip zero-width characters. Defaults to True when collapse_whitespace=True, False otherwise. Can be used independently.

Fixed execution order

Operations always execute in this order, regardless of how you specify them:

  1. Normalize — Unicode normalization
  2. Confusables — Replace homoglyphs
  3. Demojize — Expand emoji to text
  4. Strip accents — Remove combining marks
  5. Transliterate — Convert to ASCII
  6. Fold case — Case folding
  7. Strip control — Remove control characters
  8. Strip zero-width — Remove zero-width/invisible characters
  9. Collapse whitespace — Whitespace normalization

When to use which

Scenario Use
One-off text processing Text builder
Ad-hoc chains with varying steps Text builder
Processing a large dataset uniformly TextPipeline
Need explicit control over step ordering Text builder
Batch ETL / search index normalization TextPipeline