| 1 |
11
|
aaronmk
|
# Useful functions and classes
|
| 2 |
|
|
|
| 3 |
931
|
aaronmk
|
#### Function wrappers for statements
|
| 4 |
|
|
|
| 5 |
|
|
def noop(*args, **kw_args): pass
|
| 6 |
|
|
|
| 7 |
|
|
def and_(a, b): return a and b
|
| 8 |
|
|
|
| 9 |
791
|
aaronmk
|
#### Object metadata
|
| 10 |
|
|
|
| 11 |
341
|
aaronmk
|
def type_name(value): return type(value).__name__
|
| 12 |
|
|
|
| 13 |
135
|
aaronmk
|
def module(value): return type(value).__module__.split('.')
|
| 14 |
|
|
|
| 15 |
|
|
def root_module(value): return module(value)[0]
|
| 16 |
|
|
|
| 17 |
791
|
aaronmk
|
#### Basic types
|
| 18 |
|
|
|
| 19 |
|
|
class ConstraintError(ValueError):
|
| 20 |
|
|
def __init__(self, check_func, value):
|
| 21 |
795
|
aaronmk
|
ValueError.__init__(self, str(value)+' must satisfy constraint '
|
| 22 |
|
|
+check_func.__name__)
|
| 23 |
791
|
aaronmk
|
|
| 24 |
836
|
aaronmk
|
def cast(type_, val):
|
| 25 |
|
|
'''Passes None through'''
|
| 26 |
|
|
if val != None: val = type_(val)
|
| 27 |
|
|
return val
|
| 28 |
|
|
|
| 29 |
791
|
aaronmk
|
def is_str(val): return isinstance(val, basestring)
|
| 30 |
|
|
|
| 31 |
|
|
#### Iterables
|
| 32 |
|
|
|
| 33 |
135
|
aaronmk
|
def first(iter_): return iter_.next()
|
| 34 |
|
|
|
| 35 |
133
|
aaronmk
|
def skip(iter_, func):
|
| 36 |
|
|
# Advance iter while func is True
|
| 37 |
|
|
try:
|
| 38 |
|
|
while func(iter_.curr()): iter_.next()
|
| 39 |
|
|
except StopIteration: pass # nothing after the matching elements
|
| 40 |
|
|
|
| 41 |
791
|
aaronmk
|
class CheckedIter:
|
| 42 |
|
|
def __init__(self, check_func, iterable):
|
| 43 |
|
|
self.check_func = check_func
|
| 44 |
|
|
self.iter_ = iterable.__iter__()
|
| 45 |
|
|
|
| 46 |
|
|
def __iter__(self): return self
|
| 47 |
|
|
|
| 48 |
|
|
def next(self):
|
| 49 |
|
|
entry = self.iter_.next()
|
| 50 |
|
|
if self.check_func(entry): return entry
|
| 51 |
|
|
else: raise ConstraintError(self.check_func, entry)
|
| 52 |
|
|
|
| 53 |
|
|
#### Dicts
|
| 54 |
|
|
|
| 55 |
330
|
aaronmk
|
def rename_key(dict_, orig, new): dict_[new] = dict_.pop(orig)
|
| 56 |
466
|
aaronmk
|
|
| 57 |
467
|
aaronmk
|
def dict_subset(dict_, keys):
|
| 58 |
|
|
subset = dict()
|
| 59 |
|
|
for key in keys:
|
| 60 |
|
|
try: subset[key] = dict_[key]
|
| 61 |
|
|
except KeyError: pass
|
| 62 |
|
|
return subset
|
