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Dagster Data Engineering Glossary:

Tokenize

Convert data into tokens or smaller units to simplify analysis or processing.

Tokenization definition:

Tokenization is the process of breaking down a piece of text into individual words or tokens. This is a common technique used in data engineering to prepare text data for analysis.

Tokenizing example using Python:

Here are some practical examples of tokenization in data engineering using Python-specific functions. Please note that you need to have the necessary Python libraries installed in your Python environment to run this code:

Using the split() function: The split() function can be used to split a string into a list of words based on a delimiter, such as a space or a comma.

For example:

text = "This is a sample sentence."
tokens = text.split()
print(tokens)

This would output:

['This', 'is', 'a', 'sample', 'sentence.']

Using the word_tokenize() function from the NLTK library: The Natural Language Toolkit (NLTK) is a popular Python library for natural language processing. The word_tokenize() function from the NLTK library can be used to tokenize text data into individual words. For example:

import nltk
nltk.download('punkt')

from nltk.tokenize import word_tokenize

text = "This is a sample sentence."
tokens = word_tokenize(text)
print(tokens)

Will output:

['This', 'is', 'a', 'sample', 'sentence', '.']

Using regular expressions: Regular expressions can be used to define patterns for tokenizing text data. For example, the following code uses regular expressions to split a string into words based on whitespace and punctuation:

import re

text = "This is a sample sentence."
tokens = re.findall(r'\b\w+\b', text)
print(tokens)

This code would produce the following output in the terminal:

['This', 'is', 'a', 'sample', 'sentence']

Using the split() function with a regular expression pattern: The split() function can also be used with regular expression patterns to tokenize text data. For example:

import re

text = "This is a sample sentence."
tokens = re.split('\W+', text)
print(tokens)

This will yield:

['This', 'is', 'a', 'sample', 'sentence', '']

These are just a few examples of how tokenization can be used to prepare data for analysis and extract insights from text.