tensorflow:: ops:: Substr

#include <string_ops.h>

Return substrings from Tensor of strings.

Summary

For each string in the input Tensor , creates a substring starting at index pos with a total length of len .

If len defines a substring that would extend beyond the length of the input string, or if len is negative, then as many characters as possible are used.

A negative pos indicates distance within the string backwards from the end.

If pos specifies an index which is out of range for any of the input strings, then an InvalidArgumentError is thrown.

pos and len must have the same shape, otherwise a ValueError is thrown on Op creation.

NOTE : Substr supports broadcasting up to two dimensions. More about broadcasting here

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Examples

Using scalar pos and len :

input = [b'Hello', b'World']
position = 1
length = 3

output = [b'ell', b'orl']

Using pos and len with same shape as input :

input = [[b'ten', b'eleven', b'twelve'],
         [b'thirteen', b'fourteen', b'fifteen'],
         [b'sixteen', b'seventeen', b'eighteen']]
position = [[1, 2, 3],
            [1, 2, 3],
            [1, 2, 3]]
length =   [[2, 3, 4],
            [4, 3, 2],
            [5, 5, 5]]

output = [[b'en', b'eve', b'lve'],
          [b'hirt', b'urt', b'te'],
          [b'ixtee', b'vente', b'hteen']]

Broadcasting pos and len onto input :

input = [[b'ten', b'eleven', b'twelve'],
         [b'thirteen', b'fourteen', b'fifteen'],
         [b'sixteen', b'seventeen', b'eighteen'],
         [b'nineteen', b'twenty', b'twentyone']]
position = [1, 2, 3]
length =   [1, 2, 3]

output = [[b'e', b'ev', b'lve'],
          [b'h', b'ur', b'tee'],
          [b'i', b've', b'hte'],
          [b'i', b'en', b'nty']]

Broadcasting input onto pos and len :

input = b'thirteen'
position = [1, 5, 7]
length =   [3, 2, 1]

output = [b'hir', b'ee', b'n']

Raises:

• ValueError : If the first argument cannot be converted to a Tensor of dtype string .
• InvalidArgumentError : If indices are out of range.
• ValueError : If pos and len are not the same shape.

Args:

• scope: A Scope object
• input: Tensor of strings
• pos: Scalar defining the position of first character in each substring
• len: Scalar defining the number of characters to include in each substring

Optional attributes (see Attrs ):

• unit: The unit that is used to create the substring. One of: "BYTE" (for defining position and length by bytes) or "UTF8_CHAR" (for the UTF-8 encoded Unicode code points). The default is "BYTE" . Results are undefined if unit=UTF8_CHAR and the input strings do not contain structurally valid UTF-8.

Returns:

• Output : Tensor of substrings

Constructors and Destructors
Substr (const :: tensorflow::Scope & scope, :: tensorflow::Input input, :: tensorflow::Input pos, :: tensorflow::Input len)
Substr (const :: tensorflow::Scope & scope, :: tensorflow::Input input, :: tensorflow::Input pos, :: tensorflow::Input len, const Substr::Attrs & attrs)

Public attributes
operation	Operation
output	:: tensorflow::Output

Public functions
node () const	::tensorflow::Node *
operator::tensorflow::Input () const
operator::tensorflow::Output () const

Public static functions
Unit (StringPiece x)	Attrs

Structs
tensorflow:: ops:: Substr:: Attrs	Optional attribute setters for Substr .

Public attributes

operation

Operation operation

output

::tensorflow::Output output

Public functions

Substr

 Substr(
  const ::tensorflow::Scope & scope,
  ::tensorflow::Input input,
  ::tensorflow::Input pos,
  ::tensorflow::Input len
)

Substr

 Substr(
  const ::tensorflow::Scope & scope,
  ::tensorflow::Input input,
  ::tensorflow::Input pos,
  ::tensorflow::Input len,
  const Substr::Attrs & attrs
)

node

::tensorflow::Node * node() const 

operator::tensorflow::Input

 operator::tensorflow::Input() const 

operator::tensorflow::Output

 operator::tensorflow::Output() const 

Public static functions

Unit

Attrs Unit(
  StringPiece x
)