Python 3.x InvalidArgumentError:必须为带有dtype float的占位符张量“占位符2”提供一个值

我是Tensorflow的新手，正在尝试波士顿房价的线性回归。 我使用整个数据集作为训练集只是为了练习

dataset_input是输入训练示例。 dataset_output是输出训练示例

十、 Y被用作占位符，它将从我刚才描述的上述两个变量中获取输入，然后将其输入到sess.runtrain下的feed_dict，feed_dict={X:dataset_input，Y:dataset_output}。 但是在代码的某个地方，我得到了这个错误：

InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
     [[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0

以下是代码：

import tensorflow as tf
import numpy as np
import pandas as pd
from sklearn.datasets import load_boston
import matplotlib.pyplot as plt

boston=load_boston()
type(boston)
boston.feature_names

bd=pd.DataFrame(data=boston.data,columns=boston.feature_names)

bd['Price']=pd.DataFrame(data=boston.target)
np.random.shuffle(bd.values)

#bd.describe()

#bd.dtypes.index

W=tf.Variable(0.0)
b=tf.Variable(0.0)
print(bd.shape[1])

dataset_input=bd.iloc[:, 0 : bd.shape[1]-1];
dataset_input.head(2)

dataset_output=bd.iloc[:, bd.shape[1]-1]
dataset_output=dataset_output.values
dataset_output=dataset_output.reshape((bd.shape[0],1))#converted (506,) to (506,1) because in pandas 
#the shape was not changing and it was needed later in feed_dict
#dataset_output.head(2)

print("Output.shape=",dataset_output.shape)
print("Input.shape=",dataset_input.shape)

X=tf.placeholder(tf.float32, shape=(None,bd.shape[1]-1))
Y=tf.placeholder(tf.float32, shape=(None,1))

Y_=W*X+b
print(X.shape)
print(Y.shape)
#Y_=tf.convert_to_tensor(dataset_output)

loss=tf.reduce_mean(tf.square(Y_-Y))

optimizer=tf.train.GradientDescentOptimizer(0.5)
train=optimizer.minimize(loss)

init=tf.global_variables_initializer()#tf.global_variables_initializer()#tf.initialize_all_variables()
sess=tf.Session()
sess.run(init)

with tf.Session() as sess:
    epochs=1000
    sess.run(init)
    points=[ [],[] ]
    for i in range(epochs):
        sess.run(train,feed_dict={X:dataset_input,Y:dataset_output})# cannot understand whether the error is here ?
        if(i%10==0):
            points[0].append(1+i)
            points[1].append(sess.run(loss))
        if(i%100==0):
            print(i+1,sess.run(cost))
        plt.plot(points[0],points[1],'r--')
        plt.axis([0,epochs,50,600])#
        plt.show()

追溯到：

14
Output.shape= (506, 1)
Input.shape= (506, 13)
(?, 13)
(?, 1)

---------------------------------------------------------------------------
InvalidArgumentError                      Traceback (most recent call last)
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
   1038     try:
-> 1039       return fn(*args)
   1040     except errors.OpError as e:

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _run_fn(session, feed_dict, fetch_list, target_list, options, run_metadata)
   1020                                  feed_dict, fetch_list, target_list,
-> 1021                                  status, run_metadata)
   1022 

~/anaconda3/envs/Tensorflow/lib/python3.6/contextlib.py in __exit__(self, type, value, traceback)
     87             try:
---> 88                 next(self.gen)
     89             except StopIteration:

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/errors_impl.py in raise_exception_on_not_ok_status()
    465           compat.as_text(pywrap_tensorflow.TF_Message(status)),
--> 466           pywrap_tensorflow.TF_GetCode(status))
    467   finally:

InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
     [[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]

During handling of the above exception, another exception occurred:

InvalidArgumentError                      Traceback (most recent call last)
<ipython-input-35-520f8b9256aa> in <module>()
     60         if(i%10==0):
     61             points[0].append(1+i)
---> 62             points[1].append(sess.run(loss))
     63         if(i%100==0):
     64             print(i+1,sess.run(cost))

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in run(self, fetches, feed_dict, options, run_metadata)
    776     try:
    777       result = self._run(None, fetches, feed_dict, options_ptr,
--> 778                          run_metadata_ptr)
    779       if run_metadata:
    780         proto_data = tf_session.TF_GetBuffer(run_metadata_ptr)

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _run(self, handle, fetches, feed_dict, options, run_metadata)
    980     if final_fetches or final_targets:
    981       results = self._do_run(handle, final_targets, final_fetches,
--> 982                              feed_dict_string, options, run_metadata)
    983     else:
    984       results = []

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_run(self, handle, target_list, fetch_list, feed_dict, options, run_metadata)
   1030     if handle is None:
   1031       return self._do_call(_run_fn, self._session, feed_dict, fetch_list,
-> 1032                            target_list, options, run_metadata)
   1033     else:
   1034       return self._do_call(_prun_fn, self._session, handle, feed_dict,

~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
   1050         except KeyError:
   1051           pass
-> 1052       raise type(e)(node_def, op, message)
   1053 
   1054   def _extend_graph(self):

InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
     [[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]

Caused by op 'Placeholder_2', defined at:
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel_launcher.py", line 16, in <module>
    app.launch_new_instance()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/traitlets/config/application.py", line 658, in launch_instance
    app.start()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 486, in start
    self.io_loop.start()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 127, in start
    self.asyncio_loop.run_forever()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/base_events.py", line 421, in run_forever
    self._run_once()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/base_events.py", line 1431, in _run_once
    handle._run()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/events.py", line 145, in _run
    self._callback(*self._args)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 117, in _handle_events
    handler_func(fileobj, events)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
    return fn(*args, **kwargs)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 450, in _handle_events
    self._handle_recv()
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 480, in _handle_recv
    self._run_callback(callback, msg)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback
    callback(*args, **kwargs)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
    return fn(*args, **kwargs)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher
    return self.dispatch_shell(stream, msg)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell
    handler(stream, idents, msg)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 399, in execute_request
    user_expressions, allow_stdin)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/ipkernel.py", line 208, in do_execute
    res = shell.run_cell(code, store_history=store_history, silent=silent)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/zmqshell.py", line 537, in run_cell
    return super(ZMQInteractiveShell, self).run_cell(*args, **kwargs)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2662, in run_cell
    raw_cell, store_history, silent, shell_futures)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2785, in _run_cell
    interactivity=interactivity, compiler=compiler, result=result)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2903, in run_ast_nodes
    if self.run_code(code, result):
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2963, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-35-520f8b9256aa>", line 37, in <module>
    X=tf.placeholder(tf.float32, shape=(None,bd.shape[1]-1))
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/ops/array_ops.py", line 1507, in placeholder
    name=name)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/ops/gen_array_ops.py", line 1997, in _placeholder
    name=name)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/op_def_library.py", line 768, in apply_op
    op_def=op_def)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 2336, in create_op
    original_op=self._default_original_op, op_def=op_def)
  File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 1228, in __init__
    self._traceback = _extract_stack()

InvalidArgumentError (see above for traceback): You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
     [[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]

---

您试图输入到X（数据集输入）的值是一个pandas数据帧，而不是Tensorflow所期望的适当的numpy数据数组

简单地定义例如dataset_input=boston.data应该在这里起作用