5 Best Ways to Perform Unicode Operations in TensorFlow Using Python

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πŸ’‘ Problem Formulation: When working with international datasets, handling Unicode strings is crucial. TensorFlow provides multiple methods for performing Unicode operations, which are essential for natural language processing tasks. For instance, converting a dataset with Chinese characters into a UTF-8 encoded tensor and parsing it into understandable unicode strings is a typical necessity.

Method 1: Unicode encoding using tf.strings.unicode_encode

TensorFlow’s tf.strings.unicode_encode function allows the encoding of unicode characters into UTF-8 format. This method is particularly useful when preparing textual data for machine learning models that require input in encoded form.

Here’s an example:

import tensorflow as tf

# Define a tensor with Unicode characters
unicode_tensor = tf.constant([u'δ½ ε₯½', u'δΈ–η•Œ'])

# Encode the Unicode characters
encoded_tensor = tf.strings.unicode_encode(unicode_tensor, 'UTF-8')


The output of this code snippet will be:

[b'\xe4\xbd\xa0\xe5\xa5\xbd' b'\xe4\xb8\x96\xe7\x95\x8c']

The provided code creates a tensor of Unicode strings and then encodes them into UTF-8 by using the tf.strings.unicode_encode function. This is particularly beneficial when processing text data for neural networks, which typically operate on numerical data.

Method 2: Unicode decoding using tf.strings.unicode_decode

TensorFlow’s tf.strings.unicode_decode function is used to convert encoded strings back into readable Unicode characters, helping to interpret model predictions and input data during analysis.

Here’s an example:

import tensorflow as tf

# Define a tensor with UTF-8 encoded strings
encoded_tensor = tf.constant([b'\xe4\xbd\xa0\xe5\xa5\xbd', b'\xe4\xb8\x96\xe7\x95\x8c'])

# Decode the UTF-8 encoded strings
unicode_tensor = tf.strings.unicode_decode(encoded_tensor, 'UTF-8')


The output will be:

[[20320 22909]
 [19990 30028]]

This code demonstrates how to decode UTF-8 encoded strings back to Unicode code points. This allows for the analysis and processing of predictions by models in human-readable text.

Method 3: Length of Unicode strings with tf.strings.length

TensorFlow’s tf.strings.length function can compute the character length of Unicode strings, which can be crucial for tasks that require understanding text length or truncating strings to certain sizes.

Here’s an example:

import tensorflow as tf

# Define a tensor with Unicode strings
unicode_tensor = tf.constant([u'δ½ ε₯½', u'δΈ–η•Œ'])

# Get the length for each string
lengths = tf.strings.length(unicode_tensor, unit="UTF8_CHAR")


The output for this will be:

[2 2]

This snippet calculates the length of each string within a tensor containing Unicode characters, which could be useful for preprocessing steps such as padding or truncation in text data pipelines.

Method 4: Unicode Script Tokenization using tf.strings.unicode_script_tokenize

TensorFlow provides tf.strings.unicode_script_tokenize for tokenizing Unicode strings based on script boundaries. This is particularly useful for scripts where traditional whitespace tokenization is insufficient.

Here’s an example:

import tensorflow as tf

# A tensor with Unicode strings
unicode_strings = tf.constant([u'δ½ ε₯½οΌŒδΈ–η•Œγ€‚'])

# Tokenize the strings
tokens = tf.strings.unicode_script_tokenize(unicode_strings)


The output of this example will be:

[[20320 22909 65292 19990 30028 12290]]

The tf.strings.unicode_script_tokenize function tokenizes the input Unicode strings based on their script, breaking up text into tokens that correspond to distinct elements of the text, which is more effective for certain languages and scripts.

Bonus One-Liner Method 5: Unicode Split using tf.strings.unicode_split

TensorFlow offers a simple one-liner function tf.strings.unicode_split to split Unicode strings into a list of character substrings. This is easy to use for character-level tokenization.

Here’s an example:

import tensorflow as tf

# Define a tensor with a Unicode string
unicode_string = tf.constant('δ½ ε₯½δΈ–η•Œ')

# Split the Unicode string
char_list = tf.strings.unicode_split(unicode_string, 'UTF-8')


The output will be:

[b'\xe4\xbd\xa0' b'\xe5\xa5\xbd' b'\xe4\xb8\x96' b'\xe7\x95\x8c']

Utilizing tf.strings.unicode_split, a Unicode string is split into individual characters. This is particularly handy for character-level analysis or modeling.


  • Method 1: Unicode Encoding with tf.strings.unicode_encode. Strengths: Essential for model input preparation. Weaknesses: Requires understanding of encoding formats.
  • Method 2: Unicode Decoding with tf.strings.unicode_decode. Strengths: Allows easy interpretation of textual data from models. Weaknesses: Must match the correct encoding used during encoding.
  • Method 3: Unicode String Length with tf.strings.length. Strengths: Crucial for specific preprocessing tasks like padding. Weaknesses: Limited to length determination.
  • Method 4: Unicode Script Tokenization with tf.strings.unicode_script_tokenize. Strengths: Effective tokenization for languages where whitespace is not used as a delimiter. Weaknesses: Could be more complex than necessary for languages that use spaces.
  • Bonus Method 5: Unicode Split with tf.strings.unicode_split. Strengths: Quick character-level tokenization for simple use cases. Weaknesses: Does not take into account language-specific tokenization rules.