spaCy/website/docs/api/cython-classes.mdx

---
title: Cython Classes
menu:
  - ['Doc', 'doc']
  - ['Token', 'token']
  - ['Span', 'span']
  - ['Lexeme', 'lexeme']
  - ['Vocab', 'vocab']
  - ['StringStore', 'stringstore']
---

## Doc {id="doc",tag="cdef class",source="spacy/tokens/doc.pxd"}

The `Doc` object holds an array of [`TokenC`](/api/cython-structs#tokenc)
structs.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see [`Doc`](/api/doc).

</Infobox>

### Attributes {id="doc_attributes"}

| Name         | Description                                                                                              |
| ------------ | -------------------------------------------------------------------------------------------------------- |
| `mem`        | A memory pool. Allocated memory will be freed once the `Doc` object is garbage collected. ~~cymem.Pool~~ |
| `vocab`      | A reference to the shared `Vocab` object. ~~Vocab~~                                                      |
| `c`          | A pointer to a [`TokenC`](/api/cython-structs#tokenc) struct. ~~TokenC\*~~                               |
| `length`     | The number of tokens in the document. ~~int~~                                                            |
| `max_length` | The underlying size of the `Doc.c` array. ~~int~~                                                        |

### Doc.push_back {id="doc_push_back",tag="method"}

Append a token to the `Doc`. The token can be provided as a
[`LexemeC`](/api/cython-structs#lexemec) or
[`TokenC`](/api/cython-structs#tokenc) pointer, using Cython's
[fused types](http://cython.readthedocs.io/en/latest/src/userguide/fusedtypes.html).

> #### Example
>
> ```python
> from spacy.tokens cimport Doc
> from spacy.vocab cimport Vocab
>
> doc = Doc(Vocab())
> lexeme = doc.vocab.get("hello")
> doc.push_back(lexeme, True)
> assert doc.text == "hello "
> ```

| Name         | Description                                        |
| ------------ | -------------------------------------------------- |
| `lex_or_tok` | The word to append to the `Doc`. ~~LexemeOrToken~~ |
| `has_space`  | Whether the word has trailing whitespace. ~~bint~~ |

## Token {id="token",tag="cdef class",source="spacy/tokens/token.pxd"}

A Cython class providing access and methods for a
[`TokenC`](/api/cython-structs#tokenc) struct. Note that the `Token` object does
not own the struct. It only receives a pointer to it.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see [`Token`](/api/token).

</Infobox>

### Attributes {id="token_attributes"}

| Name    | Description                                                                |
| ------- | -------------------------------------------------------------------------- |
| `vocab` | A reference to the shared `Vocab` object. ~~Vocab~~                        |
| `c`     | A pointer to a [`TokenC`](/api/cython-structs#tokenc) struct. ~~TokenC\*~~ |
| `i`     | The offset of the token within the document. ~~int~~                       |
| `doc`   | The parent document. ~~Doc~~                                               |

### Token.cinit {id="token_cinit",tag="method"}

Create a `Token` object from a `TokenC*` pointer.

> #### Example
>
> ```python
> token = Token.cinit(&doc.c[3], doc, 3)
> ```

| Name     | Description                                                                |
| -------- | -------------------------------------------------------------------------- |
| `vocab`  | A reference to the shared `Vocab`. ~~Vocab~~                               |
| `c`      | A pointer to a [`TokenC`](/api/cython-structs#tokenc) struct. ~~TokenC\*~~ |
| `offset` | The offset of the token within the document. ~~int~~                       |
| `doc`    | The parent document. ~~int~~                                               |

## Span {id="span",tag="cdef class",source="spacy/tokens/span.pxd"}

A Cython class providing access and methods for a slice of a `Doc` object.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see [`Span`](/api/span).

</Infobox>

### Attributes {id="span_attributes"}

| Name         | Description                                                                   |
| ------------ | ----------------------------------------------------------------------------- |
| `doc`        | The parent document. ~~Doc~~                                                  |
| `start`      | The index of the first token of the span. ~~int~~                             |
| `end`        | The index of the first token after the span. ~~int~~                          |
| `start_char` | The index of the first character of the span. ~~int~~                         |
| `end_char`   | The index of the last character of the span. ~~int~~                          |
| `label`      | A label to attach to the span, e.g. for named entities. ~~attr_t (uint64_t)~~ |

## Lexeme {id="lexeme",tag="cdef class",source="spacy/lexeme.pxd"}

A Cython class providing access and methods for an entry in the vocabulary.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see [`Lexeme`](/api/lexeme).

</Infobox>

### Attributes {id="lexeme_attributes"}

| Name    | Description                                                                   |
| ------- | ----------------------------------------------------------------------------- |
| `c`     | A pointer to a [`LexemeC`](/api/cython-structs#lexemec) struct. ~~LexemeC\*~~ |
| `vocab` | A reference to the shared `Vocab` object. ~~Vocab~~                           |
| `orth`  | ID of the verbatim text content. ~~attr_t (uint64_t)~~                        |

## Vocab {id="vocab",tag="cdef class",source="spacy/vocab.pxd"}

A Cython class providing access and methods for a vocabulary and other data
shared across a language.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see [`Vocab`](/api/vocab).

</Infobox>

### Attributes {id="vocab_attributes"}

| Name      | Description                                                                                                |
| --------- | ---------------------------------------------------------------------------------------------------------- |
| `mem`     | A memory pool. Allocated memory will be freed once the `Vocab` object is garbage collected. ~~cymem.Pool~~ |
| `strings` | A `StringStore` that maps string to hash values and vice versa. ~~StringStore~~                            |
| `length`  | The number of entries in the vocabulary. ~~int~~                                                           |

### Vocab.get {id="vocab_get",tag="method"}

Retrieve a [`LexemeC*`](/api/cython-structs#lexemec) pointer from the
vocabulary.

> #### Example
>
> ```python
> lexeme = vocab.get("hello")
> ```

| Name        | Description                                       |
| ----------- | ------------------------------------------------- |
| `string`    | The string of the word to look up. ~~str~~        |
| **RETURNS** | The lexeme in the vocabulary. ~~const LexemeC\*~~ |

### Vocab.get_by_orth {id="vocab_get_by_orth",tag="method"}

Retrieve a [`LexemeC*`](/api/cython-structs#lexemec) pointer from the
vocabulary.

> #### Example
>
> ```python
> lexeme = vocab.get_by_orth(doc[0].lex.norm)
> ```

| Name        | Description                                            |
| ----------- | ------------------------------------------------------ |
| `orth`      | ID of the verbatim text content. ~~attr_t (uint64_t)~~ |
| **RETURNS** | The lexeme in the vocabulary. ~~const LexemeC\*~~      |

## StringStore {id="stringstore",tag="cdef class",source="spacy/strings.pxd"}

A lookup table to retrieve strings by 64-bit hashes.

<Infobox variant="warning">

This section documents the extra C-level attributes and methods that can't be
accessed from Python. For the Python documentation, see
[`StringStore`](/api/stringstore).

</Infobox>

### Attributes {id="stringstore_attributes"}

| Name   | Description                                                                                                      |
| ------ | ---------------------------------------------------------------------------------------------------------------- |
| `mem`  | A memory pool. Allocated memory will be freed once the `StringStore` object is garbage collected. ~~cymem.Pool~~ |
| `keys` | A list of hash values in the `StringStore`. ~~vector[hash_t] \(vector[uint64_t])~~                               |