我想匹配一个看起来像目录的变量列表,例如:
Same/Same2/Foot/Ankle/Joint/Actuator/Sensor/Temperature/Value=4.123
Same/Same2/Battery/Name=SomeString
Same/Same2/Home/Land/Some/More/Stuff=0.34
"子目录"的长度是一个有上限的变量(上面是9)。我想把每个子目录分组,除了上面我命名为"Same"的第一个子目录。
我能想到的最好的是:
^(?:([^/]+)/){4,8}([^/]+)=(.*)
它已经查找4-8个子目录,但只分组最后一个。为什么?是否有更好的解决方案使用组量词?
编辑:解决。将使用split()代替。
import re
regx = re.compile('(?:(?<=A)|(?<=/)).+?(?=/|Z)')
for ss in ('Same/Same2/Foot/Ankle/Joint/Actuator/Sensor/Temperature/Value=4.123',
'Same/Same2/Battery/Name=SomeString',
'Same/Same2/Home/Land/Some/More/Stuff=0.34'):
print ss
print regx.findall(ss)
print
编辑1
现在您已经给出了更多关于您想要获得的信息(_"Same/Same2/Battery/Name=SomeString成为SAME2_BATTERY_NAME=SomeString"_)可以提出更好的解决方案:使用正则表达式或split(), + replace()
import re
from os import sep
sep2 = r'\' if sep=='\' else '/'
pat = '^(?:.+?%s)(.+$)' % sep2
print 'pat==%sn' % pat
ragx = re.compile(pat)
for ss in ('SameSame2FootAnkleJointActuatorSensorTemperatureValue=4.123',
'SameSame2BatteryName=SomeString',
'SameSame2HomeLandSomeMoreStuff=0.34'):
print ss
print ragx.match(ss).group(1).replace(sep,'_')
print ss.split(sep,1)[1].replace(sep,'_')
print
结果pat==^(?:.+?\)(.+$)
SameSame2FootAnkleJointActuatorSensorTemperatureValue=4.123
Same2_Foot_Ankle_Joint_Actuator_Sensor_Temperature_Value=4.123
Same2_Foot_Ankle_Joint_Actuator_Sensor_Temperature_Value=4.123
SameSame2BatteryName=SomeString
Same2_Battery_Name=SomeString
Same2_Battery_Name=SomeString
SameSame2HomeLandSomeMoreStuff=0.34
Same2_Home_Land_Some_More_Stuff=0.34
Same2_Home_Land_Some_More_Stuff=0.34
编辑2
重新阅读你的评论,我意识到我没有考虑到你想要在'='符号之前而不是在它之后的字符串部分上。
因此,这段新代码公开了3个方法来满足这个要求。你可以选择你喜欢哪一个:
import re
from os import sep
sep2 = r'\' if sep=='\' else '/'
pot = '^(?:.+?%s)(.+?)=([^=]*$)' % sep2
print 'pot==%sn' % pot
rogx = re.compile(pot)
pet = '^(?:.+?%s)(.+?(?==[^=]*$))' % sep2
print 'pet==%sn' % pet
regx = re.compile(pet)
for ss in ('SameSame2FootAnkleJointSensorValue=4.123',
'SameSame2BatteryName=SomeString',
'SameSame2OceanAtlanticNorth=',
'SameSame2MathsAddition\2+2=4Simple=ohoh'):
print ss + 'n' + len(ss)*'-'
print 'rogx groups '.rjust(32),rogx.match(ss).groups()
a,b = ss.split(sep,1)[1].rsplit('=',1)
print 'split split '.rjust(32),(a,b)
print 'split split join upper replace %s=%s' % (a.replace(sep,'_').upper(),b)
print 'regx split group '.rjust(32),regx.match(ss.split(sep,1)[1]).group()
print 'regx split sub '.rjust(32),
regx.sub(lambda x: x.group(1).replace(sep,'_').upper(), ss)
print
result,在Windows平台上
pot==^(?:.+?\)(.+?)=([^=]*$)
pet==^(?:.+?\)(.+?(?==[^=]*$))
SameSame2FootAnkleJointSensorValue=4.123
----------------------------------------------
rogx groups ('Same2\Foot\Ankle\Joint\Sensor\Value', '4.123')
split split ('Same2\Foot\Ankle\Joint\Sensor\Value', '4.123')
split split join upper replace SAME2_FOOT_ANKLE_JOINT_SENSOR_VALUE=4.123
regx split group Same2FootAnkleJointSensorValue
regx split sub SAME2_FOOT_ANKLE_JOINT_SENSOR_VALUE=4.123
SameSame2BatteryName=SomeString
----------------------------------
rogx groups ('Same2\Battery\Name', 'SomeString')
split split ('Same2\Battery\Name', 'SomeString')
split split join upper replace SAME2_BATTERY_NAME=SomeString
regx split group Same2BatteryName
regx split sub SAME2_BATTERY_NAME=SomeString
SameSame2OceanAtlanticNorth=
--------------------------------
rogx groups ('Same2\Ocean\Atlantic\North', '')
split split ('Same2\Ocean\Atlantic\North', '')
split split join upper replace SAME2_OCEAN_ATLANTIC_NORTH=
regx split group Same2OceanAtlanticNorth
regx split sub SAME2_OCEAN_ATLANTIC_NORTH=
SameSame2MathsAddition2+2=4Simple=ohoh
-------------------------------------------
rogx groups ('Same2\Maths\Addition\2+2=4\Simple', 'ohoh')
split split ('Same2\Maths\Addition\2+2=4\Simple', 'ohoh')
split split join upper replace SAME2_MATHS_ADDITION_2+2=4_SIMPLE=ohoh
regx split group Same2MathsAddition2+2=4Simple
regx split sub SAME2_MATHS_ADDITION_2+2=4_SIMPLE=ohoh
我可能误解了您想要做的事情,但是下面是不使用regex的方法:
for entry in list_of_vars:
key, value = entry.split('=')
key_components = key.split('/')
if 4 <= len(key_components) <= 8:
# here the actual work is done
print "%s=%s" % ('_'.join(key_components[1:]).upper(), value)
使用split?
>>> p='Same/Same2/Foot/Ankle/Joint/Actuator/Sensor/Temperature/Value=4.123'
>>> p.split('/')
['Same', 'Same2', 'Foot', 'Ankle', 'Joint', 'Actuator', 'Sensor', 'Temperature', 'Value=4.123']
同样,如果你想要key/val对,你可以这样做…
>>> s = p.split('/')
>>> s[-1].split('=')
['Value', '4.123']
主题的几个变化。首先,我总是发现regexen非常神秘,以至于无法维护,所以我编写了pyparsing模块。在我看来,我看着你的代码,然后想,"哦,这是一个'/'分隔的字符串列表,一个'='符号,然后是某种右值。"这将非常直接地转换为pyparsing解析器定义代码。通过在解析器中到处添加一个名称("key"one_answers"value",类似于regex中的命名组),输出非常容易处理。
data="""
Same/Same2/Foot/Ankle/Joint/Actuator/Sensor/Temperature/Value=4.123
Same/Same2/Battery/Name=SomeString
Same/Same2/Home/Land/Some/More/Stuff=0.34""".splitlines()
from pyparsing import Word, alphas, alphanums, Word, nums, QuotedString, delimitedList
wd = Word(alphas, alphanums)
number = Word(nums+'+-', nums+'.').setParseAction(lambda t:float(t[0]))
rvalue = wd | number | QuotedString('"')
defn = delimitedList(wd, '/')('key') + '=' + rvalue('value')
for d in data:
result = defn.parseString(d)
其次,我质疑您定义所有这些变量名的方法——基于数据动态创建变量名是一种公认的代码气味(不一定是坏的,但您可能真的想重新考虑这种方法)。我使用递归默认字典来创建一个可导航的结构,以便您可以轻松地执行诸如"查找作为"Same2"的子元素的所有条目(在本例中为"Foot","Battery"one_answers"Home")之类的操作-当试图筛选在locals()中找到的一些变量名称集合时,这种工作更加困难,在我看来,您最终将重新解析这些名称以重建键层次结构。
from collections import defaultdict
class recursivedefaultdict(defaultdict):
def __init__(self, attrFactory=int):
self.default_factory = lambda : type(self)(attrFactory)
self._attrFactory = attrFactory
def __getattr__(self, attr):
newval = self._attrFactory()
setattr(self, attr, newval)
return newval
table = recursivedefaultdict()
# parse each entry, and accumulate into hierarchical dict
for d in data:
# use pyparsing parser, gives us key (list of names) and value
result = defn.parseString(d)
t = table
for k in result.key[:-1]:
t = t[k]
t[result.key[-1]] = result.value
# recursive method to iterate over hierarchical dict
def showTable(t, indent=''):
for k,v in t.items():
print indent+k,
if isinstance(v,dict):
print
showTable(v, indent+' ')
else:
print v
showTable(table)
打印:
Same
Same2
Foot
Ankle
Joint
Actuator
Sensor
Temperature
Value 4.123
Battery
Name SomeString
Home
Land
Some
More
Stuff 0.34
如果你真的设置定义这些变量名,那么在pyparsing中添加一些有用的解析操作将在解析时重新格式化已解析的数据,以便之后可以直接处理:
wd = Word(alphas, alphanums)
number = Word(nums+'+-', nums+'.').setParseAction(lambda t:float(t[0]))
rvaluewd = wd.copy().setParseAction(lambda t: '"%s"' % t[0])
rvalue = rvaluewd | number | QuotedString('"')
defn = delimitedList(wd, '/')('key') + '=' + rvalue('value')
def joinNamesWithAllCaps(tokens):
tokens["key"] = '_'.join(map(str.upper, tokens.key))
defn.setParseAction(joinNamesWithAllCaps)
for d in data:
result = defn.parseString(d)
print result.key,'=', result.value
打印:
SAME_SAME2_FOOT_ANKLE_JOINT_ACTUATOR_SENSOR_TEMPERATURE_VALUE = 4.123
SAME_SAME2_BATTERY_NAME = "SomeString"
SAME_SAME2_HOME_LAND_SOME_MORE_STUFF = 0.34
(请注意,这还将SomeString值括在引号中,以便生成的赋值语句是有效的Python。)