I want to convert a string such as 'a=b,a=c,a=d,b=e' into a dict of lists {'a': ['b', 'c', 'd'], 'b': ['e']} in Python 2.6.
My current solution is this:
def merge(d1, d2):
for k, v in d2.items():
if k in d1:
if type(d1[k]) != type(list()):
d1[k] = list(d1[k])
d1[k].append(v)
else:
d1[k] = list(v)
return d1
record = 'a=b,a=c,a=d,b=e'
print reduce(merge, map(dict,[[x.split('=')] for x in record.split(',')]))
which I'm sure is unnec开发者_运维问答essarily complicated.
Any better solutions?
d = {}
for i in 'a=b,a=c,a=d,b=e'.split(","):
k,v = i.split("=")
d.setdefault(k,[]).append(v)
print d
or, if you're using python > 2.4, you can use defaultdict
from collections import defaultdict
d = defaultdict(list)
for i in 'a=b,a=c,a=d,b=e'.split(","):
k,v = i.split("=")
d[k].append(v)
print d
>>> result={}
>>> mystr='a=b,a=c,a=d,b=e'
>>> for k, v in [s.split('=') for s in mystr.split(',')]:
... result[k] = result.get(k, []) + [v]
...
>>> result
{'a': ['b', 'c', 'd'], 'b': ['e']}
How about...
STR = "a=c,b=d,a=x,a=b"
d = {} # An empty dictionary to start with.
# We split the string at the commas first, and each substr at the '=' sign
pairs = (subs.split('=') for subs in STR.split(','))
# Now we add each pair to a dictionary of lists.
for key, value in pairs:
d[key] = d.get(key, []) + [value]
Using a regex allow to do the work of two splits in only one:
import re
ch ='a=b,a=c ,a=d, b=e'
dic = {}
for k,v in re.findall('(\w+)=(\w+)\s*(?:,|\Z)',ch):
dic.setdefault(k,[]).append(v)
print dic
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