My tools of the trade for python programming.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

65 lines
1.6 KiB

#!/usr/bin/ipython -pylab
#
# $Id: sugar.py,v 1.3 2010-02-19 18:42:15 wirawan Exp $
#
# Created: 20100121
# Wirawan Purwanto
#
# Syntactic sugar for python programming. May not be efficient, but many
# of these tools are nice for quick-and-dirty programming.
# Beware of their caveats!
#
#
import sys
def ifelse(cond, trueval, *args):
"""An alternative to python's own ternary operator, but with multiple
conditions to test (like chained if-else-if-else... which is found in
e.g. m4 language).
This is of course only a syntactic sugar with its inefficiency and
dangers (all expressions are evaluated before choosing which one is to
select). So, beware!"""
if cond:
return trueval
else:
i = 0
while i+1 < len(args):
if args[i]: return args[i+1]
i += 2
if i < len(args): return args[i]
return None # Fallback solution: "None"
if sys.version_info < (2,4):
def sorted(List):
rslt = [ L for L in List ] # == L.copy()
rslt.sort()
return rslt
else:
#print dir(globals())
sorted = sorted
#print dir(globals())
def dict_slice(Dict, *keys):
"""Returns a shallow copy of the subset of a given dict (or an otherwise
hashable object) with a given set of keys.
Example: if d = {'abc': 12, 'def': 7, 'ghi': 32, 'jkl': 98 }
then dict_slice(d, 'abc', 'ghi') will yield {'abc': 12, 'ghi': 32 }
"""
return dict([ (k, Dict[k]) for k in keys ])
def dict_join(*dicts):
"""Join multiple dicts into one, updating duplicate keys from left-to-right
manner.
Thus the key from the rightmost dict will take precedence."""
rslt = {}
for d in dicts:
rslt.update(d)
return rslt