tokenize
Parse texts and separate them into lists of tokens (words, lemmas, etc.).
Usage
The following example shows how the step can be used in a recipe.Examples
Examples
E.g. to convert text strings to lists of lower-cased words, ignoring any tokens that represent
punctuation (punct), URLs and stop words (stops), use:
Inputs & Outputs
The following are the inputs expected by the step and the outputs it produces. These are generally columns (ds.first_name), datasets (ds or ds[["first_name", "last_name"]]) or models (referenced
by name e.g. "churn-clf").
Inputs
Inputs
A column of texts to separate into tokens.
An (optional) column identifying the languages of the corresponding texts. It is used to identify the correct model (spaCy)
to use for each text. If the dataset doesn’t contain such a column yet, it can be created using the
infer_language step.
Ideally, languages should be expressed as two-letter
ISO 639-1 language codes, such as “en”, “es” or “de” for
English, Spanish or German respectively. We also detect fully spelled out names such as “english”, “German”, “allemande”
etc., but it is not guaranteed that we will recognize all possible spellings correctly always, so ISO codes should be
preferred.Alternatively, if all texts are in the same language, it can be identified with the language parameter instead.Outputs
Outputs
A column of lists containing the tokens extracted from the texts.
Configuration
The following parameters can be used to configure the behaviour of the step by including them in a json object as the last “input” to the step, i.e.step(..., {"param": "value", ...}) -> (output).
Parameters
Parameters
Whether to enable support for additional languages.
By default, Arabic (“ar”), Catalan (“ca”), Basque (“eu”), and Turkish (“tu”) are not enabled,
since they’re supported only by a different class of language models (stanfordNLP’s Stanza)
that is much slower than the rest. This parameter can be used to enable them.
Minimum number (or proportion) of texts to include a language in processing.
Any texts in a language with fewer documents than these will be ignored. Can be useful to speed up
processing when there is noise in the input languages, and when ignoring languages with a small number of
documents only is acceptable. Values smaller than 1 will be interpreted as a proportion of all texts, and
values greater than or equal to 1 as an absolute number of documents.
Options
Options
number.Values must be in the following range:
The language of inputs texts.
If all texts are in the same language, it can be specified here instead of passing it as an input column. The language will be used to identify the correct spaCy model to parse and analyze the texts. For allowed values, see the comment regarding the
lang column above.Configure how tokens are extracted and represented in the output.
Define the kinds of tokens to extract, how to represent them, and their minimum or maximum frequency in the
dataset to be included in the result.
Properties
Properties
Representation of the individual tokens to extract.
I.e. whether verbatim (text/ortho), lower(-case) or lemmatized. Also see spaCy’s attribute reference
in this table for further information.Values must be one of the following:
orthlemmalowertext
Which kinds of tokens to exclude.
Valid filters are stop words (
stops), URLs (urls), punctuation (punct), digits,
tokens containing non-alphabetic characters (non_alpha), and tokens containing non-ascii
characters (non_ascii).Array items
Array items
Each item in array.Values must be one of the following:
stops urls punct digits non_alpha non_asciiToken frequency filter.
Filters tokens based on the number of texts they occur in.
Properties
Properties
Minimum number of rows.
Tokens not occurring in at least these many rows (texts) will be excluded.Values must be in the following range:
Maximum proportion of rows.
Tokens occurring in more than this proportion of rows (texts) will be excluded.Values must be in the following range:
Keep n most frequent tokens.
Whether to always include the n most frequent tokens, independent of the other filter parameters.
Set to
null to ignore.Values must be in the following range:Exclude n most frequent tokens.
Even if they passed the other filter conditions.Values must be in the following range:
Filter per language.
Apply filter conditions separately to texts grouped by language, rather than across all texts.