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Return substrings from Tensor
of strings.
tf.compat.v2.strings.substr(
input, pos, len, unit='BYTE', name=None
)
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, 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.
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']
Args | |
---|---|
input
|
A Tensor of type string . Tensor of strings
|
pos
|
A Tensor . Must be one of the following types: int32 , int64 .
Scalar defining the position of first character in each substring
|
len
|
A Tensor . Must have the same type as pos .
Scalar defining the number of characters to include in each substring
|
unit
|
An optional string from: "BYTE", "UTF8_CHAR" . Defaults to "BYTE" .
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.
|
name
|
A name for the operation (optional). |
Returns | |
---|---|
A Tensor of type string .
|