我正在尝试从python 2.7中的任意文件夹位置动态加载模块和包。它适用于裸露的单个文件模块。但是尝试加载包中有点困难。
我能想到的最好的方法是在包（文件夹）中加载 init .py文件。但是比方说我有这个：
root:
mod.py
package:
__init__.py
sub.py
如果mod.py包含：
from package import sub
使用我当前的加载代码（下面），它将失败，说明没有名为“sub”的包，除非我将以下内容添加到package/__init__.py
import sub
我必须想象这是因为当你导入一个包时，它通常也会扫描其中的所有其他子文件。我是否也需要手动执行此操作，或者是否有类似于imp.load_source的方法也可以处理包文件夹？
正在加载代码：
import md5
import sys
import os.path
import imp
import traceback
import glob
def load_package(path, base):
try:
try:
sys.path.append(path + "/" + base)
init = path + "/" + base + "/__init__.py"
if not os.path.exists(init):
return None
fin = open(init, 'rb')
return (base, imp.load_source(base, init, fin))
finally:
try: fin.close()
except: pass
except ImportError, x:
traceback.print_exc(file = sys.stderr)
raise
except:
traceback.print_exc(file = sys.stderr)
raise
def load_module(path):
try:
try:
code_dir = os.path.dirname(path)
code_file = os.path.basename(path)
base = code_file.replace(".py", "")
fin = open(path, 'rb')
hash = md5.new(path).hexdigest() + "_" + code_file
return (base, imp.load_source(base, path, fin))
finally:
try: fin.close()
except: pass
except ImportError, x:
traceback.print_exc(file = sys.stderr)
raise
except:
traceback.print_exc(file = sys.stderr)
raise
def load_folder(dir):
sys.path.append(dir)
mods = {}
for p in glob.glob(dir + "/*/"):
base = p.replace("\\", "").replace("/", "")
base = base.replace(dir.replace("\\", "").replace("/", ""), "")
package = load_package(dir, base)
if package:
hash, pack = package
mods[hash] = pack
for m in glob.glob(dir + "/*.py"):
hash, mod = load_module(m)
mods[hash] = mod
return mods
答案 0 :(得分：1)
下面的代码在功能上等同于您的代码模块traceback.print_exc（您应该让客户端处理 - 如果不处理，异常最终会打印出来）：
def _load_package(path, base):
sys.path.append(path + "/" + base)
init = path + "/" + base + "/__init__.py"
if not os.path.exists(init):
return None, None
with open(init, 'rb') as fin:
return base, imp.load_source(base, init, fin)
def _load_module(path):
code_file = os.path.basename(path)
base = code_file.replace(".py", "")
with open(path, 'rb') as fin:
return base, imp.load_source(base, path, fin)
def load_folder(dir):
sys.path.append(dir)
mods = {}
for p in glob.glob(dir + "/*/"):
base = p.replace("\\", "").replace("/", "")
base = base.replace(dir.replace("\\", "").replace("/", ""), "")
hash, pack = _load_package(dir, base)
if hash: mods[hash] = pack
for m in glob.glob(dir + "/*.py"): ##: /*/*.py
hash, mod = _load_module(m)
mods[hash] = mod
return mods
## My added code
print('Python %s on %s' % (sys.version, sys.platform))
root_ = r'C:\Dropbox\eclipse_workspaces\python\sandbox\root'
def depyc(root, _indent=''): # deletes .pyc which will end up being imported
if not _indent: print '\nListing', root
for p in os.listdir(root):
name = _indent + p
abspath = os.path.join(root, p)
if os.path.isdir(abspath):
print name + ':'
depyc(abspath, _indent=_indent + ' ')
else:
name_ = name[-4:]
if name_ == '.pyc':
os.remove(abspath)
continue
print name
if not _indent: print
depyc(root_)
load_folder(root_)
打印：
Python 2.7.10 (default, May 23 2015, 09:40:32) [MSC v.1500 32 bit (Intel)] on win32
Listing C:\Dropbox\eclipse_workspaces\python\sandbox\root
mod.py
package:
sub.py
__init__.py
C:\Dropbox\eclipse_workspaces\python\sandbox\root/package/__init__.py imported!
C:\Dropbox\eclipse_workspaces\python\sandbox\root\mod.py imported!
mod.py，sub.py和__init__.py只包含
print(__file__ + u' imported!')
现在将mod.py修改为：
from package import sub
print(__file__ + u' imported!')
Listing....
C:\Dropbox\eclipse_workspaces\python\sandbox\root/package/__init__.py imported! <### this may move around ###>
Traceback (most recent call last):
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 57, in <module>
load_folder(root_)
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 31, in load_folder
hash, mod = _load_module(m)
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 20, in _load_module
return base, imp.load_source(base, path, fin)
File "C:\Dropbox\eclipse_workspaces\python\sandbox\root\mod.py", line 1, in <module>
from package import sub
ImportError: cannot import name sub
注意错误是＆＃34;无法导入名称sub＆＃34;而不是＆＃34;没有名为＆＃34; sub＆＃34;＆＃34;的包。那么为什么不能呢？
修改__init__.py：
# package/__init__.py
print(__file__ + u' imported!')
print '__name__', '->', __name__
print '__package__', '->', __package__
print '__path__', '->', __path__
打印：
Listing...
C:\Dropbox\eclipse_workspaces\python\sandbox\root/package/__init__.py imported! <### not really ###>
__name__ -> package
__package__ -> None
__path__ ->
Traceback (most recent call last):
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 59, in <module>
load_folder(root_)
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 30, in load_folder
hash, pack = _load_package(dir, base)
File "C:/Users/MrD/.PyCharm40/config/scratches/load_folder.py", line 14, in _load_package
init = imp.load_source(base, init, fin)
File "C:\Dropbox\eclipse_workspaces\python\sandbox\root/package/__init__.py", line 5, in <module>
print '__path__', '->', __path__
NameError: name '__path__' is not defined
直接导入它会打印：
>>> sys.path.extend([r'C:\Dropbox\eclipse_workspaces\python\sandbox\root'])
>>> import package
C:\Dropbox\eclipse_workspaces\python\sandbox\root\package\__init__.py imported!
__name__ -> package
__package__ -> None
__path__ -> ['C:\\Dropbox\\eclipse_workspaces\\python\\sandbox\\root\\package']
所以将_load_package修改为：
def _load_package(path, base):
pkgDir = os.path.abspath(os.path.join(path, base))
init = os.path.join(pkgDir, "__init__.py")
if not os.path.exists(init):
return None, None
file, pathname, description = imp.find_module(base, [path])
print file, pathname, description # None, pkgDir, ('', '', 5)
pack = sys.modules.get(base, None) # load_module will reload - yak!
if pack is None:
sys.modules[base] = pack = imp.load_module(base, file, pathname, description)
return base, pack
解决它：
...
if pack is None:
sys.modules[base] = pack = imp.load_module(base, None, '', description)
pack.__path__ = [pkgDir]
或您的原始代码：
with open(init, 'rb') as fin:
source = imp.load_source(base, init, fin)
source.__path__ = path + "/" + base
return base, source
所以，正在发生的事情是该程序包依赖其__path __属性才能正常运行。
保持黑客攻击并提出：
import sys
import os.path
import imp
def _load_(root, name):
file_object, pathname, description = imp.find_module(name, [root])
pack = sys.modules.get(name, None)
try:
if pack is None:
pack = imp.load_module(name, file_object, pathname, description)
else:
print 'In cache', pack
finally:
if file_object is not None: file_object.close()
return name, pack
def load_folder(root):
# sys.path.append(root)
mods = {}
paths = [(item, os.path.join(root, item)) for item in os.listdir(root)]
packages = filter(lambda path_tuple: os.path.exists(
os.path.join((path_tuple[1]), "__init__.py")), paths)
py_files = filter(lambda path_tuple: path_tuple[0][-3:] == '.py', paths)
del paths
# first import packages as in original - modules may import from them
for path, _abspath in packages:
print 'Importing', _abspath
key, mod = _load_(root, name=path) # will use pyc if available!
mods[key] = mod
# then modules
for path, _abspath in py_files:
print 'Importing', _abspath
key, mod = _load_(root, name=path[:-3])
mods[key] = mod
return mods
我合并了包和模块，加载代码丢弃imp.load_source（一个不那么棘手的函数）并依赖于imp.load_module。我不直接使用sys.path，因为imp.load_module will reload [!]我检查了sys.modules缓存。返回的mods dict完全未经测试 - 您必须以某种方式实现哈希（_abspath应该足够）。
运行方式：
def depyc(root, rmpyc, _indent=''):
if not _indent: print '\nListing', root
for p in os.listdir(root):
name = _indent + p
abspath = os.path.join(root, p)
if os.path.isdir(abspath):
print name + ':'
depyc(abspath, rmpyc, _indent=_indent + ' ')
else:
if rmpyc and name[-4:] == '.pyc':
os.remove(abspath)
continue
print name
if not _indent: print
## Run ##
print('Python %s on %s' % (sys.version, sys.platform))
root_ = os.path.join(os.getcwdu(), u'root')
depyc(root_, False) # False will end up importing the pyc files !
load_folder(root_)
测试各种场景 -
示例root/目录的代码为here