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Wraps a python function and uses it as a TensorFlow op.
tf.compat.v1.py_func(
func, inp, Tout, stateful=True, name=None
)
Given a python function func
, which takes numpy arrays as its
arguments and returns numpy arrays as its outputs, wrap this function as an
operation in a TensorFlow graph. The following snippet constructs a simple
TensorFlow graph that invokes the np.sinh()
NumPy function as a operation
in the graph:
def my_func(x):
# x will be a numpy array with the contents of the placeholder below
return np.sinh(x)
input = tf.compat.v1.placeholder(tf.float32)
y = tf.compat.v1.py_func(my_func, [input], tf.float32)
The body of the function (i.e.
func
) will not be serialized in aGraphDef
. Therefore, you should not use this function if you need to serialize your model and restore it in a different environment.The operation must run in the same address space as the Python program that calls
tf.compat.v1.py_func()
. If you are using distributed TensorFlow, you must run atf.distribute.Server
in the same process as the program that callstf.compat.v1.py_func()
and you must pin the created operation to a device in that server (e.g. usingwith tf.device():
).
E.g.
import tensorflow as tf
import numpy as np
def make_synthetic_data(i):
return np.cast[np.uint8](i) * np.ones([20,256,256,3],
dtype=np.float32) / 10.
def preprocess_fn(i):
ones = tf.py_function(make_synthetic_data,[i],tf.float32)
ones.set_shape(tf.TensorShape([None, None, None, None]))
ones = tf.image.resize(ones, [224,224])
return ones
ds = tf.data.Dataset.range(10)
ds = ds.map(preprocess_fn)
Args:
func: A Python function, which accepts ndarray
objects as arguments and
returns a list of ndarray
objects (or a single ndarray
). This function
must accept as many arguments as there are tensors in inp
, and these
argument types will match the corresponding tf.Tensor
objects in inp
.
The returns ndarray
s must match the number and types defined Tout
.
Important Note: Input and output numpy ndarray
s of func
are not
guaranteed to be copies. In some cases their underlying memory will be
shared with the corresponding TensorFlow tensors. In-place modification
or storing func
input or return values in python datastructures
without explicit (np.)copy can have non-deterministic consequences.
inp: A list of Tensor
objects.
Tout: A list or tuple of tensorflow data types or a single tensorflow data
type if there is only one, indicating what func
returns.
stateful: (Boolean.) If True, the function should be considered stateful. If
a function is stateless, when given the same input it will return the same
output and have no observable side effects. Optimizations such as common
subexpression elimination are only performed on stateless operations.
name: A name for the operation (optional).
Returns | |
---|---|
A list of Tensor or a single Tensor which func computes.
|