# Data preparation¶

.nlp Data preparation Preparing text newParser Creates a parser parseURLs Parse URLs into dictionaries containing their constituent components

Finding part-of-speech tags in a corpus findPOSRuns Find tokens of specific POS types in a text

## Preparing text¶

Operations can be pre-run on a corpus, with the results cached to a table, which can be persisted, allowing for manipulation in q.

Operations undertaken to parse the dataset:

operation effect
Tokenization Splits the words; e.g. John’s becomes John as one token, and ‘s as a second
Sentence detection Characters at which a sentence starts and ends
Part-of-speech tagger Parses the sentences into tokens and gives each token a label e.g. lemma, pos, tag etc.
Lemmatization Converts to a base form e.g. ran (verb) to run (verb)

The text of Moby Dick was used in the examples.

// Read in data
text:"\n"sv read0:mobydick.txt
mobyDick:(text ss "CHAPTER ")cut removeBadNewlines text

## Finding part-of-speech tags in a corpus¶

This is a quick way to find all of the nouns, adverbs, etc. in a corpus. There are two types of part-of-speech (POS) tags you can find:

## .nlp.findPOSRuns¶

Find tokens of specific POS types in a text

.nlp.findPOSRuns[tagtype;tags;parsedDict]

Where

• tagtype is uniPos or pennPos (symbol atom)
• tags is one or more POS tags (symbol atom or vector)
• parsedDict is a dictionary containing a single parsed text (as returned by nlp.newParser)

returns a two-item list:

1. Tokens in the text of type tags (symbol vector)
2. Indexes of the first occurrence of each token (long vector)

Importing a novel from a plain text file, and finding all the proper nouns in the first chapter of Moby Dick:

q)fields:texttokenslemmaspennPOSisStopsentCharsstartssentIndiceskeywords
q)myparser:.nlp.newParser[en;fields]
q)parsedTab:myparser mobyDick
q)parsedDict:parsedTab 0;
q).nlp.findPOSRuns[pennPOS;NNPNNPS;parsedDict]
ishmael          ,5
precisely--      ,13
november         ,76
cato             ,161
manhattoes       ,213
mole             ,247

The parsedDict argument must contain keys: tokens and pennPOS or uniPOS

## .nlp.newParser¶

Create a parser

.nlp.newParser[spacyModel;fields]

Where

• spacyModel is a spaCy model or language (symbol)
• columns are the columns you want in the result (symbol atom or vector)

returns a function to parse the text.

The optional fields are:

column       type                    content
---------------------------------------------------------------------------
text         list of characters      Original text
tokens       list of symbols         Tokenized text
sentChars    list of lists of longs  Indexes of starts and ends of sentences
sentIndices  list of integers        Indexes of first token of each sentence
pennPOS      list of symbols         The Penn Treebank tagset
uniPOS       list of symbols         The Universal tagset
lemmas       list of symbols         The base form of the word
isStop       boolean                 Is the token part of the stop list?
likeEmail    boolean                 Does the token resembles an email?
likeURL      boolean                 Does the token resembles a URL?
likeNumber   boolean                 Does the token resembles a number?
keywords     list of dictionaries    Significance of each term
starts       long                    Index that a token starts at

The resulting function is applied to a list of strings.

Spell check can also be performed on the text by passing in spell as a column name. This updates any misspelt words to their most likely alternative. This is performed on text prior to parsing. (SpaCy does not support spell check on Windows systems.)

Parsing the novel Moby Dick:

// Creating a parsed table
q)fields:texttokenslemmaspennPOSisStopsentCharsstartssentIndiceskeywords
q)myparser:.nlp.newParser[en;fields]
q)parsedTab:myparser mobyDick
q)cols parsedTab
texttokenslemmaspennPOSisStopsentCharsstartssentIndiceskeywords
Chinese and Japanese language support

.nlp.newParser also supports Chinese (zh) and Japanese (ja) tokenization. These languages are only in the alpha stage of development within SpaCy so all functionality may not be available.

KxSystems/nlp for installation instructions

## .nlp.parseURLs¶

Parse URLs into dictionaries containing their constituent components

.nlp.parseURLs url

Where url is a URL as string, returns a dictionary of information about the scheme, domain name, and other URL information.

q).nlp.parseURLs "https://www.google.ca:1234/test/index.html;myParam?foo=bar&quux=blort#abc=123&def=456"
scheme    | "https"
fragment  | "abc=123&def=456"`