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aaronmk
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# Useful functions and classes
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931
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aaronmk
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#### Function wrappers for statements
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def noop(*args, **kw_args): pass
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def and_(a, b): return a and b
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791
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aaronmk
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#### Object metadata
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341
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aaronmk
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def type_name(value): return type(value).__name__
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135
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aaronmk
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def module(value): return type(value).__module__.split('.')
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def root_module(value): return module(value)[0]
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791
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aaronmk
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#### Basic types
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class ConstraintError(ValueError):
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def __init__(self, check_func, value):
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795
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aaronmk
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ValueError.__init__(self, str(value)+' must satisfy constraint '
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+check_func.__name__)
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791
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aaronmk
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836
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aaronmk
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def cast(type_, val):
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'''Passes None through'''
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if val != None: val = type_(val)
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return val
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791
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aaronmk
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def is_str(val): return isinstance(val, basestring)
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#### Iterables
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135
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aaronmk
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def first(iter_): return iter_.next()
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133
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aaronmk
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def skip(iter_, func):
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# Advance iter while func is True
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try:
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while func(iter_.curr()): iter_.next()
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except StopIteration: pass # nothing after the matching elements
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934
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aaronmk
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def list_subset(list_, idxs):
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subset = []
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for idx in idxs:
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try: subset.append(list_[idx])
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except IndexError: pass
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return subset
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791
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aaronmk
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class CheckedIter:
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def __init__(self, check_func, iterable):
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self.check_func = check_func
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self.iter_ = iterable.__iter__()
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def __iter__(self): return self
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def next(self):
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entry = self.iter_.next()
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if self.check_func(entry): return entry
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else: raise ConstraintError(self.check_func, entry)
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#### Dicts
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330
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aaronmk
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def rename_key(dict_, orig, new): dict_[new] = dict_.pop(orig)
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466
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aaronmk
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467
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aaronmk
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def dict_subset(dict_, keys):
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subset = dict()
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for key in keys:
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try: subset[key] = dict_[key]
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except KeyError: pass
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return subset
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