我编写的脚本涉及从标准multipath.conf配置文件中添加/删除多路径“对象”，例如：
# This is a basic configuration file with some examples, for device mapper
# multipath.
## Use user friendly names, instead of using WWIDs as names.
defaults {
user_friendly_names yes
}
##
devices {
device {
vendor "SolidFir"
product "SSD SAN"
path_grouping_policy multibus
getuid_callout "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
path_selector "service-time 0"
path_checker tur
hardware_handler "0"
failback immediate
rr_weight uniform
rr_min_io 1000
rr_min_io_rq 1
features "0"
no_path_retry 24
prio const
}
}
multipaths {
multipath {
wwid 36f47acc1000000006167347a00000041
alias dwqa-ora-fs
}
multipath {
wwid 36f47acc1000000006167347a00000043
alias dwqa-ora-grid
}
multipath {
wwid 36f47acc1000000006167347a00000044
alias dwqa-ora-dwqa1
}
multipath {
wwid 36f47acc1000000006167347a000000ae
alias dwqa-ora-dwh2d10-1
}
multipath {
wwid 36f47acc1000000006167347a000000f9
alias dwqa-ora-testdg-1
}
}
所以我要做的就是读取这个文件并将其存储在嵌套的python字典（或嵌套字典列表）中。我们现在可以忽略注释行（以＃开头）。我没有为此提出一个明确/简明的解决方案。
这是我的部分解决方案（还没有给我预期的输出，但它已经接近了）
def nonblank_lines(f):
for l in f:
line = l.rstrip()
if line:
yield line
def __parse_conf__(self):
conf = []
with open(self.conf_file_path) as f:
for line in nonblank_lines(f):
if line.strip().endswith("{"): # opening bracket, start of new list of dictionaries
current_dictionary_key = line.split()[0]
current_dictionary = { current_dictionary_key : None }
conf.append(current_dictionary)
elif line.strip().endswith("}"): # closing bracket, end of new dictionary
pass
# do nothing...
elif not line.strip().startswith("#"):
if current_dictionary.values() == [None]:
# New dictionary... we should be appending to this one
current_dictionary[current_dictionary_key] = [{}]
current_dictionary = current_dictionary[current_dictionary_key][0]
key = line.strip().split()[0]
val = " ".join(line.strip().split()[1:])
current_dictionary[key] = val
这是结果字典（列表'conf'）：
[{'defaults': [{'user_friendly_names': 'yes'}]},
{'devices': None},
{'device': [{'failback': 'immediate',
'features': '"0"',
'getuid_callout': '"/lib/udev/scsi_id --whitelisted --device=/dev/%n"',
'hardware_handler': '"0"',
'no_path_retry': '24',
'path_checker': 'tur',
'path_grouping_policy': 'multibus',
'path_selector': '"service-time 0"',
'prio': 'const',
'product': '"SSD SAN"',
'rr_min_io': '1000',
'rr_min_io_rq': '1',
'rr_weight': 'uniform',
'vendor': '"SolidFir"'}]},
{'multipaths': None},
{'multipath': [{'alias': 'dwqa-ora-fs',
'wwid': '36f47acc1000000006167347a00000041'}]},
{'multipath': [{'alias': 'dwqa-ora-grid',
'wwid': '36f47acc1000000006167347a00000043'}]},
{'multipath': [{'alias': 'dwqa-ora-dwqa1',
'wwid': '36f47acc1000000006167347a00000044'}]},
{'multipath': [{'alias': 'dwqa-ora-dwh2d10-1',
'wwid': '36f47acc1000000006167347a000000ae'}]},
{'multipath': [{'alias': 'dwqa-ora-testdg-1',
'wwid': '36f47acc1000000006167347a000000f9'}]},
{'multipath': [{'alias': 'dwqa-ora-testdp10-1',
'wwid': '"SSolidFirSSD SAN 6167347a00000123f47acc0100000000"'}]}]
显然，“无”应该用它下面的嵌套字典替换，但我无法使这部分工作。
有什么建议吗？或者更好的方法来解析这个文件并将其存储在python数据结构中？
答案 0 :(得分：1)
尝试这样的事情：
def parse_conf(conf_lines):
config = []
# iterate on config lines
for line in conf_lines:
# remove left and right spaces
line = line.rstrip().strip()
if line.startswith('#'):
# skip comment lines
continue
elif line.endswith('{'):
# new dict (notice the recursion here)
config.append({line.split()[0]: parse_conf(conf_lines)})
else:
# inside a dict
if line.endswith('}'):
# end of current dict
break
else:
# parameter line
line = line.split()
if len(line) > 1:
config.append({line[0]: " ".join(line[1:])})
return config
该函数将进入配置文件的嵌套级别（感谢recursion以及conf_lines对象为iterator的事实）并创建包含的字典列表其他词典。不幸的是，您必须再次将每个嵌套字典放入列表中，因为在示例文件中显示了 multipath 如何重复，但在Python字典中，键必须是唯一的。所以你列一个清单。
您可以使用示例配置文件对其进行测试，如下所示：
with open('multipath.conf','r') as conf_file:
config = parse_conf(conf_file)
# show multipath config lines as an example
for item in config:
if 'multipaths' in item:
for multipath in item['multipaths']:
print multipath
# or do something more useful
输出结果为：
{'multipath': [{'wwid': '36f47acc1000000006167347a00000041'}, {'alias': 'dwqa-ora-fs'}]}
{'multipath': [{'wwid': '36f47acc1000000006167347a00000043'}, {'alias': 'dwqa-ora-grid'}]}
{'multipath': [{'wwid': '36f47acc1000000006167347a00000044'}, {'alias': 'dwqa-ora-dwqa1'}]}
{'multipath': [{'wwid': '36f47acc1000000006167347a000000ae'}, {'alias': 'dwqa-ora-dwh2d10-1'}]}
{'multipath': [{'wwid': '36f47acc1000000006167347a000000f9'}, {'alias': 'dwqa-ora-testdg-1'}]}
答案 1 :(得分：1)
如果您不使用递归，则需要某种方法来跟踪您的级别。但即使这样，也很难引用父母或兄弟姐妹来添加数据（我失败了）。这是基于Daniele Barresi提到的可迭代输入递归的另一种观点：
数据：
inp = """
# This is a basic configuration file with some examples, for device mapper
# multipath.
## Use user friendly names, instead of using WWIDs as names.
defaults {
user_friendly_names yes
}
##
devices {
device {
vendor "SolidFir"
product "SSD SAN"
path_grouping_policy multibus
getuid_callout "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
path_selector "service-time 0"
path_checker tur
hardware_handler "0"
failback immediate
rr_weight uniform
rr_min_io 1000
rr_min_io_rq 1
features "0"
no_path_retry 24
prio const
}
}
multipaths {
multipath {
wwid 36f47acc1000000006167347a00000041
alias dwqa-ora-fs
}
multipath {
wwid 36f47acc1000000006167347a00000043
alias dwqa-ora-grid
}
multipath {
wwid 36f47acc1000000006167347a00000044
alias dwqa-ora-dwqa1
}
multipath {
wwid 36f47acc1000000006167347a000000ae
alias dwqa-ora-dwh2d10-1
}
multipath {
wwid 36f47acc1000000006167347a000000f9
alias dwqa-ora-testdg-1
}
}
"""
代码：
import re
level = 0
def recurse( data ):
""" """
global level
out = []
level += 1
for line in data:
l = line.strip()
if l and not l.startswith('#'):
match = re.search(r"\s*(\w+)\s*(?:{|(?:\"?\s*([^\"]+)\"?)?)", l)
if not match:
if l == '}':
level -= 1
return out # recursion, up one level
else:
key, value = match.groups()
if not value:
print( " "*level, level, key )
value = recurse( data ) # recursion, down one level
else:
print( " "*level, level, key, value)
out.append( [key,value] )
return out # once
result = recurse( iter(inp.split('\n')) )
import pprint
pp = pprint.PrettyPrinter(indent=4)
pp.pprint(result)
带有嵌套[“key”，value]对的结果列表：
[ ['defaults', [['user_friendly_names', 'yes']]],
[ 'devices',
[ [ 'device',
[ ['vendor', 'SolidFir'],
['product', 'SSD SAN'],
['path_grouping_policy', 'multibus'],
[ 'getuid_callout',
'/lib/udev/scsi_id --whitelisted --device=/dev/%n'],
['path_selector', 'service-time 0'],
['path_checker', 'tur'],
['hardware_handler', '0'],
['failback', 'immediate'],
['rr_weight', 'uniform'],
['rr_min_io', '1000'],
['rr_min_io_rq', '1'],
['features', '0'],
['no_path_retry', '24'],
['prio', 'const']]]]],
[ 'multipaths',
[ [ 'multipath',
[ ['wwid', '36f47acc1000000006167347a00000041'],
['alias', 'dwqa-ora-fs']]],
[ 'multipath',
[ ['wwid', '36f47acc1000000006167347a00000043'],
['alias', 'dwqa-ora-grid']]],
[ 'multipath',
[ ['wwid', '36f47acc1000000006167347a00000044'],
['alias', 'dwqa-ora-dwqa1']]],
[ 'multipath',
[ ['wwid', '36f47acc1000000006167347a000000ae'],
['alias', 'dwqa-ora-dwh2d10-1']]],
[ 'multipath',
[ ['wwid', '36f47acc1000000006167347a000000f9'],
['alias', 'dwqa-ora-testdg-1']]]]]]
答案 2 :(得分：1)
多路径配置有点难解析。这是我使用的（最初基于 daniele-barresi 的回答），输出比其他示例更容易使用。
def get_multipath_conf():
def parse_conf(conf_lines, parent=None):
config = {}
for line in conf_lines:
line = line.split('#',1)[0].strip()
if line.endswith('{'):
key = line.split('{', 1)[0].strip()
value = parse_conf(conf_lines, parent=key)
if key+'s' == parent:
if type(config) is dict:
config = []
config.append(value)
else:
config[key] = value
else:
# inside a dict
if line.endswith('}'):
# end of current dict
break
else:
# parameter line
line = line.split(' ',1)
if len(line) > 1:
key = line[0]
value = line[1].strip().strip("'").strip('"')
config[key] = value
return config
return parse_conf(open('/etc/multipath.conf','r'))
这是输出：
{'blacklist': {'devnode': '^(ram|raw|loop|fd|md|dm-|sr|scd|st|sda|sdb)[0-9]*$'},
'defaults': {'find_multipaths': 'yes',
'max_polling_interval': '4',
'polling_interval': '2',
'reservation_key': '0x1'},
'devices': [{'detect_checker': 'no',
'hardware_handler': '1 alua',
'no_path_retry': '5',
'path_checker': 'tur',
'prio': 'alua',
'product': 'iSCSI Volume',
'user_friendly_names': 'yes',
'vendor': 'StorMagic'}]}