人工智能深度学习入门练习之（23）TensorFlow2基础语法之练习

1、张量求和

①、tensorflow1.x版

import tensorflow.compat.v1 as tf
tf.disable_v2_behavior() # 使用静态图模式运行以下代码
assert tf.__version__.startswith('2.')

# 1.创建计算图阶段
# 创建2个输入端子，指定类型和名字
a_ph = tf.placeholder(tf.float32, name='variable_a')
b_ph = tf.placeholder(tf.float32, name='variable_b')
# 创建输出端子的运算操作，并命名
c_op = tf.add(a_ph, b_ph, name='variable_c')

# 2.运行计算图阶段
# 创建运行环境
sess = tf.InteractiveSession()
# 初始化操作也需要作为操作运行
init = tf.global_variables_initializer()
sess.run(init) # 运行初始化操作，完成初始化
# 运行输出端子，需要给输入端子赋值
c_numpy = sess.run(c_op, feed_dict={a_ph: 2., b_ph: 4.})
# 运算完输出端子才能得到数值类型的c_numpy
print('a+b=',c_numpy)

结果：

C:\Anaconda3\python.exe "C:\Program Files\JetBrains\PyCharm 2019.1.1\helpers\pydev\pydevconsole.py" --mode=client --port=63269
import sys; print('Python %s on %s' % (sys.version, sys.platform))
sys.path.extend(['C:\\app\\PycharmProjects', 'C:/app/PycharmProjects'])
Python 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 7.12.0 -- An enhanced Interactive Python. Type '?' for help.
PyDev console: using IPython 7.12.0
Python 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)] on win32
runfile('C:/app/PycharmProjects/tensorflow/Test/__init__.py', wdir='C:/app/PycharmProjects/tensorflow/Test')
2020-11-10 15:25:43.753169: W tensorflow/stream_executor/platform/default/dso_loader.cc:59] Could not load dynamic library 'cudart64_101.dll'; dlerror: cudart64_101.dll not found
2020-11-10 15:25:43.755830: I tensorflow/stream_executor/cuda/cudart_stub.cc:29] Ignore above cudart dlerror if you do not have a GPU set up on your machine.
WARNING:tensorflow:From C:\Anaconda3\lib\site-packages\tensorflow\python\compat\v2_compat.py:96: disable_resource_variables (from tensorflow.python.ops.variable_scope) is deprecated and will be removed in a future version.
Instructions for updating:
non-resource variables are not supported in the long term
2020-11-10 15:26:07.126862: I tensorflow/core/platform/cpu_feature_guard.cc:142] This TensorFlow binary is optimized with oneAPI Deep Neural Network Library (oneDNN)to use the following CPU instructions in performance-critical operations:  AVX2
To enable them in other operations, rebuild TensorFlow with the appropriate compiler flags.
2020-11-10 15:26:07.199289: I tensorflow/compiler/xla/service/service.cc:168] XLA service 0x1ccbe5249e0 initialized for platform Host (this does not guarantee that XLA will be used). Devices:
2020-11-10 15:26:07.201115: I tensorflow/compiler/xla/service/service.cc:176]   StreamExecutor device (0): Host, Default Version
2020-11-10 15:26:07.206639: W tensorflow/stream_executor/platform/default/dso_loader.cc:59] Could not load dynamic library 'nvcuda.dll'; dlerror: nvcuda.dll not found
2020-11-10 15:26:07.209239: W tensorflow/stream_executor/cuda/cuda_driver.cc:312] failed call to cuInit: UNKNOWN ERROR (303)
a+b= 6.0

②、tensorflow2.x版

import tensorflow as  tf
a=tf.constant(2.0)
b=tf.constant(4.0)
print('{0}+{1}={2}'.format(a,b,a+b))

结果：

C:\Anaconda3\python.exe "C:\Program Files\JetBrains\PyCharm 2019.1.1\helpers\pydev\pydevconsole.py" --mode=client --port=63589
import sys; print('Python %s on %s' % (sys.version, sys.platform))
sys.path.extend(['C:\\app\\PycharmProjects', 'C:/app/PycharmProjects'])
Python 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 7.12.0 -- An enhanced Interactive Python. Type '?' for help.
PyDev console: using IPython 7.12.0
Python 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)] on win32
runfile('C:/app/PycharmProjects/tensorflow/Test/__init__.py', wdir='C:/app/PycharmProjects/tensorflow/Test')
2020-11-10 15:46:36.564267: W tensorflow/stream_executor/platform/default/dso_loader.cc:59] Could not load dynamic library 'cudart64_101.dll'; dlerror: cudart64_101.dll not found
2020-11-10 15:46:36.566052: I tensorflow/stream_executor/cuda/cudart_stub.cc:29] Ignore above cudart dlerror if you do not have a GPU set up on your machine.
2.0+4.0=6.0