背景
anaconda虚拟环境+windows10+python3.6.10+tensorflow2.2.0
错误1：Failed to import pydot. You must install pydot and graphviz for pydotprint to work.
错误1错误出错点：
使用plot_model将模型导出文件时报错。
from tensorflow.keras.utils import plot_model
plot_model(model, to_file='model.png')
Failed to import pydot. You must install pydot and graphviz for
pydotprintto work.
错误1原因：
找不到pydot、graphviz。
错误1解决：
（1）安装pydot（pydot_ng或者pydotplus）
pip install pydot
pip install pydot_ng
pip install pydotplus
注意：有的教程说不能安装pydot，需要安装pydot_ng，我个人觉得这是不正确的说法，至少不能解决我的问题。
这三个安装任意一个都可以，根据源码（envs\dlpy\Lib\site-packages\tensorflow\python\keras\utils\vis_utils.py文件）：
try:
print("aaaa")
# pydot-ng is a fork of pydot that is better maintained.
import pydot_ng as pydot
except ImportError:
# pydotplus is an improved version of pydot
try:
import pydotplus as pydot
except ImportError:
# Fall back on pydot if necessary.
try:
import pydot
except ImportError:
pydot = None
可以看到这里会去依次尝试导入pydot_ng、pydotplus、pydot，所以下载哪个都是一样的。
(2)安装graphviz
- 官网地址，我这里下载的是graphviz-install-2.44.1-win64
- 下载完成后，点击exe文件进行安装。（注意安装路径）
-
安装成功后，添加环境变量。（上一步中的路径，我这里是C:\Program Files\Graphviz 2.44.1\bin）
添加环境变量
（3）重新激活anaconda虚拟环境，测试graphviz是否可以使用。
dot -version
出现graphviz版本信息：
graphviz版本信息
错误2：GraphViz's executables not found
错误2出错点：
找不到GraphViz
GraphViz's executables not found
错误2原因：
根据源码，判定graphviz路径有问题。
def find_graphviz():
"""Locate Graphviz's executables in the system.
Tries three methods:
First: Windows Registry (Windows only)
This requires Mark Hammond's pywin32 is installed.
Secondly: Search the path
It will look for 'dot', 'twopi' and 'neato' in all the directories
specified in the PATH environment variable.
Thirdly: Default install location (Windows only)
It will look for 'dot', 'twopi' and 'neato' in the default install
location under the "Program Files" directory.
It will return a dictionary containing the program names as keys
and their paths as values.
If this fails, it returns None.
"""
# Method 1 (Windows only)
if os.sys.platform == 'win32':
HKEY_LOCAL_MACHINE = 0x80000002
KEY_QUERY_VALUE = 0x0001
RegOpenKeyEx = None
RegQueryValueEx = None
RegCloseKey = None
try:
import win32api
RegOpenKeyEx = win32api.RegOpenKeyEx
RegQueryValueEx = win32api.RegQueryValueEx
RegCloseKey = win32api.RegCloseKey
except ImportError:
# Print a messaged suggesting they install these?
pass
try:
import ctypes
def RegOpenKeyEx(key, subkey, opt, sam):
result = ctypes.c_uint(0)
ctypes.windll.advapi32.RegOpenKeyExA(key, subkey, opt, sam,
ctypes.byref(result))
return result.value
def RegQueryValueEx(hkey, valuename):
data_type = ctypes.c_uint(0)
data_len = ctypes.c_uint(1024)
data = ctypes.create_string_buffer(1024)
# this has a return value, which we should probably check
ctypes.windll.advapi32.RegQueryValueExA(
hkey, valuename, 0, ctypes.byref(data_type),
data, ctypes.byref(data_len))
return data.value
RegCloseKey = ctypes.windll.advapi32.RegCloseKey
except ImportError:
# Print a messaged suggesting they install these?
pass
if RegOpenKeyEx is not None:
# Get the GraphViz install path from the registry
hkey = None
potentialKeys = [
"SOFTWARE\\ATT\\Graphviz",
"SOFTWARE\\AT&T Research Labs\\Graphviz"]
for potentialKey in potentialKeys:
try:
hkey = RegOpenKeyEx(
HKEY_LOCAL_MACHINE,
potentialKey, 0, KEY_QUERY_VALUE)
if hkey is not None:
path = RegQueryValueEx(hkey, "InstallPath")
RegCloseKey(hkey)
# The regitry variable might exist, left by
# old installations but with no value, in those cases
# we keep searching...
if not path:
continue
# Now append the "bin" subdirectory:
path = os.path.join(path, "bin")
progs = __find_executables(path)
if progs is not None:
return progs
except Exception:
pass
else:
break
# Method 2 (Linux, Windows etc)
if 'PATH' in os.environ:
for path in os.environ['PATH'].split(os.pathsep):
progs = __find_executables(path)
if progs is not None:
return progs
# Method 3 (Windows only)
if os.sys.platform == 'win32':
# Try and work out the equivalent of "C:\Program Files" on this
# machine (might be on drive D:, or in a different language)
if 'PROGRAMFILES' in os.environ:
# Note, we could also use the win32api to get this
# information, but win32api may not be installed.
path = os.path.join(os.environ['PROGRAMFILES'], 'ATT',
'GraphViz', 'bin')
else:
# Just in case, try the default...
path = r"C:\Program Files\att\Graphviz\bin"
progs = __find_executables(path)
if progs is not None:
return progs
for path in (
'/usr/bin', '/usr/local/bin',
'/opt/local/bin',
'/opt/bin', '/sw/bin', '/usr/share',
'/Applications/Graphviz.app/Contents/MacOS/'):
progs = __find_executables(path)
if progs is not None:
return progs
# Failed to find GraphViz
return None
错误2解决方法：
在上面的方法中手动写入graphviz路径，我这里是C:\Program Files\Graphviz 2.44.1\bin
path = r"C:\Program Files\Graphviz 2.44.1\bin"
progs = __find_executables(path)
if progs is not None:
return progs
修改完后的该方法为：
def find_graphviz():
"""Locate Graphviz's executables in the system.
Tries three methods:
First: Windows Registry (Windows only)
This requires Mark Hammond's pywin32 is installed.
Secondly: Search the path
It will look for 'dot', 'twopi' and 'neato' in all the directories
specified in the PATH environment variable.
Thirdly: Default install location (Windows only)
It will look for 'dot', 'twopi' and 'neato' in the default install
location under the "Program Files" directory.
It will return a dictionary containing the program names as keys
and their paths as values.
If this fails, it returns None.
"""
# Method 1 (Windows only)
if os.sys.platform == 'win32':
HKEY_LOCAL_MACHINE = 0x80000002
KEY_QUERY_VALUE = 0x0001
RegOpenKeyEx = None
RegQueryValueEx = None
RegCloseKey = None
try:
import win32api
RegOpenKeyEx = win32api.RegOpenKeyEx
RegQueryValueEx = win32api.RegQueryValueEx
RegCloseKey = win32api.RegCloseKey
except ImportError:
# Print a messaged suggesting they install these?
pass
try:
import ctypes
def RegOpenKeyEx(key, subkey, opt, sam):
result = ctypes.c_uint(0)
ctypes.windll.advapi32.RegOpenKeyExA(key, subkey, opt, sam,
ctypes.byref(result))
return result.value
def RegQueryValueEx(hkey, valuename):
data_type = ctypes.c_uint(0)
data_len = ctypes.c_uint(1024)
data = ctypes.create_string_buffer(1024)
# this has a return value, which we should probably check
ctypes.windll.advapi32.RegQueryValueExA(
hkey, valuename, 0, ctypes.byref(data_type),
data, ctypes.byref(data_len))
return data.value
RegCloseKey = ctypes.windll.advapi32.RegCloseKey
except ImportError:
# Print a messaged suggesting they install these?
pass
if RegOpenKeyEx is not None:
# Get the GraphViz install path from the registry
hkey = None
potentialKeys = [
"SOFTWARE\\ATT\\Graphviz",
"SOFTWARE\\AT&T Research Labs\\Graphviz"]
for potentialKey in potentialKeys:
try:
hkey = RegOpenKeyEx(
HKEY_LOCAL_MACHINE,
potentialKey, 0, KEY_QUERY_VALUE)
if hkey is not None:
path = RegQueryValueEx(hkey, "InstallPath")
RegCloseKey(hkey)
# The regitry variable might exist, left by
# old installations but with no value, in those cases
# we keep searching...
if not path:
continue
# Now append the "bin" subdirectory:
path = os.path.join(path, "bin")
progs = __find_executables(path)
if progs is not None:
return progs
except Exception:
pass
else:
break
# Method 2 (Linux, Windows etc)
if 'PATH' in os.environ:
for path in os.environ['PATH'].split(os.pathsep):
progs = __find_executables(path)
if progs is not None:
return progs
path = r"C:\Program Files\Graphviz 2.44.1\bin"
progs = __find_executables(path)
if progs is not None:
return progs
# Method 3 (Windows only)
if os.sys.platform == 'win32':
# Try and work out the equivalent of "C:\Program Files" on this
# machine (might be on drive D:, or in a different language)
if 'PROGRAMFILES' in os.environ:
# Note, we could also use the win32api to get this
# information, but win32api may not be installed.
path = os.path.join(os.environ['PROGRAMFILES'], 'ATT',
'GraphViz', 'bin')
else:
# Just in case, try the default...
path = r"C:\Program Files\att\Graphviz\bin"
progs = __find_executables(path)
if progs is not None:
return progs
for path in (
'/usr/bin', '/usr/local/bin',
'/opt/local/bin',
'/opt/bin', '/sw/bin', '/usr/share',
'/Applications/Graphviz.app/Contents/MacOS/'):
progs = __find_executables(path)
if progs is not None:
return progs
# Failed to find GraphViz
return None
错误3：pydot_ng.InvocationException:Program terminated with status:1. stderr follows: Format:“ps” not
错误3原因：
错误3原因
错误3解决方法：
dot -c
结果
重新运行代码，可以正常使用。
正常使用
