Robot Framework 代码3之pythonpathsetter.py

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#     
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#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
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"""Module that adds directories needed by Robot to sys.path when imported."""

import sys
import os
import fnmatch


def norm_path(path):
    path = os.path.normpath(path)
    # If windows or cyqwin (os.path.normcase not supported in jython)
    if os.sep == '\\' or sys.platform.count('cygwin') > 0:
        path = path.lower()
    return path

def add_path(path, to_beginning=False):
    if not path:
        return
    path = norm_path(path)
    if path not in sys.path and os.path.exists(path):
        if to_beginning:
            sys.path.insert(0, path)
        else:
            sys.path.append(path)
                
def remove_path(path):
    path = norm_path(path)
    while path in sys.path:
        sys.path.remove(path)


sys.path = [ norm_path(p) for p in sys.path ]

ROBOTDIR = norm_path(os.path.dirname(os.path.abspath(__file__)))
print ROBOTDIR
PARENTDIR = os.path.dirname(ROBOTDIR)

add_path(os.path.join(ROBOTDIR, 'libraries'), to_beginning=True)
add_path(PARENTDIR, to_beginning=True)
# Handles egg installations
if fnmatch.fnmatchcase(os.path.basename(PARENTDIR), 'robotframework-*.egg'):
    add_path(os.path.dirname(PARENTDIR), to_beginning=True)

# Remove ROBOTDIR dir to disallow importing robot internal modules directly
remove_path(ROBOTDIR)

# Elements from PYTHONPATH. By default it is not processed in Jython and in
# Python valid non-absolute paths may be ignored.
PYPATH = os.environ.get('PYTHONPATH')
if PYPATH:
    for path in PYPATH.split(os.pathsep):
        add_path(path)
    del path

# Current dir (it seems to be in Jython by default so let's be consistent)
add_path('.')

del norm_path, add_path, remove_path, ROBOTDIR, PARENTDIR, PYPATH


文件路径：C:\Python26\Lib\site-packages\robot\pythonpathsetter.py

函数norm_path：用于将windows或者cyqwin的目录转换为小写。如果系统分隔符号os.sep为"\",则为windows。如果sys.platform有cygwin，则为cygwin，后面那种虚拟机不建议使用。

函数add_path：添加搜索路径，默认添加至末尾。

函数remove_path：删除搜索路径。通过while，有多个PATH变量也可以删除

PARENTDIR = os.path.dirname(ROBOTDIR)计算出上已成目录，也算一点技巧。

如果是用egg方式安装，把egg文件的目录也加入搜索路径。注意调用了fnmatch，fnmatch 模块使用模式来匹配文件名。

remove_path(ROBOTDIR)是为了防止直接导入robot模块。
PYTHONPATH一般不会使用，这里也加到搜索路径。
添加当前目录
删除相关的函数和变量。