def _fields(self, indexes, errors_ok=False):
"""
Given a tuple of indexes
Return a 'return_type' containing given indexes of
the nested seqs in iter(self).
If errors_ok=True, ignores errors where self
has asymmetric nested sequences or non-iterable elements.
"""
# initialize return value with GrepFieldMixin
rv = make([], GrepFieldMixin)
# create subsequences containing given indexes
for elem in self:
sublist = make([], GrepFieldMixin)
try:
for i in indexes:
sublist.append(elem[i])
except Exception, e:
if errors_ok and \
(isinstance(e, TypeError) or isinstance(e, IndexError)):
continue
raise
#print 'sublist', sublist # debug
rv.append(sublist)
def _grep(self, value, seq, parent):
"""Depth-first search for value in seq and nested-seqs
Return flattened list of elements containing value.
if parent=True, return parent seq containing value"""
# Initialize return value
rv = make([], GrepFieldMixin)
for x in seq:
append = False
recurse = True
# Did we find an exact match?
if value == x:
append = True
try:
# Strings: is val in string?
match = False
if isinstance(x, str) and value in x:
append = True
# Match on edge condition
if len(x) == 1:
if isinstance(x, str) and value in x[0] or value == x[0]:
x = x[0]
append = True
recurse = False
except Exception, e:
pass # likely not iterable or 'value in x' not possible
if append:
if parent:
rv.append(seq)
break
else:
rv.append(x)
continue
# Recurse over relevant sub-seqs
if hasattr(x, '__iter__') and recurse:
rv.extend(self._grep(value, x, parent))
def grepfieldable(inst):
"""add mixin to instance"""
return make(inst, GrepFieldMixin)