def test_lookupone():
t1 = (('foo', 'bar'), ('a', 1), ('b', 2), ('b', 3))
# lookup one column on another under strict mode
try:
lookupone(t1, 'foo', 'bar', strict=True)
except DuplicateKeyError:
pass # expected
else:
assert False, 'expected error'
# lookup one column on another under, not strict
actual = lookupone(t1, 'foo', 'bar', strict=False)
expect = {'a': 1, 'b': 2} # first value wins
eq_(expect, actual)
# test default value - tuple of whole row
actual = lookupone(t1, 'foo', strict=False) # no value selector
expect = {'a': ('a', 1), 'b': ('b', 2)} # first wins
eq_(expect, actual)
t2 = (('foo', 'bar', 'baz'), ('a', 1, True), ('b', 2, False),
('b', 3, True), ('b', 3, False))
# test value selection
actual = lookupone(t2, 'foo', ('bar', 'baz'), strict=False)
expect = {'a': (1, True), 'b': (2, False)}
eq_(expect, actual)
# test compound key
actual = lookupone(t2, ('foo', 'bar'), 'baz', strict=False)
expect = {('a', 1): True, ('b', 2): False, ('b', 3): True} # first wins
eq_(expect, actual)
def iterhashlookupjoin(left, right, lkey, rkey, missing, lprefix, rprefix):
lit = iter(left)
lhdr = next(lit)
rhdr, rit = iterpeek(right) # need the whole lot to pass to lookup
rlookup = lookupone(rit, rkey, strict=False)
# determine indices of the key fields in left and right tables
lkind = asindices(lhdr, lkey)
rkind = asindices(rhdr, rkey)
# construct functions to extract key values from left table
lgetk = operator.itemgetter(*lkind)
# determine indices of non-key fields in the right table
# (in the output, we only include key fields from the left table - we
# don't want to duplicate fields)
rvind = [i for i in range(len(rhdr)) if i not in rkind]
rgetv = rowgetter(*rvind)
# determine the output fields
if lprefix is None:
outhdr = list(lhdr)
else:
outhdr = [(str(lprefix) + str(f))
for f in lhdr]
if rprefix is None:
outhdr.extend(rgetv(rhdr))
else:
outhdr.extend([(str(rprefix) + str(f))
for f in rgetv(rhdr)])
yield tuple(outhdr)
# define a function to join rows
def joinrows(_lrow, _rrow):
# start with the left row
_outrow = list(_lrow)
# extend with non-key values from the right row
_outrow.extend(rgetv(_rrow))
return tuple(_outrow)
for lrow in lit:
k = lgetk(lrow)
if k in rlookup:
rrow = rlookup[k]
yield joinrows(lrow, rrow)
else:
outrow = list(lrow) # start with the left row
# extend with missing values in place of the right row
outrow.extend([missing] * len(rvind))
yield tuple(outrow)
def iterhashlookupjoin(left, right, lkey, rkey, missing, lprefix, rprefix):
lit = iter(left)
lhdr = next(lit)
rhdr, rit = iterpeek(right) # need the whole lot to pass to lookup
rlookup = lookupone(rit, rkey, strict=False)
# determine indices of the key fields in left and right tables
lkind = asindices(lhdr, lkey)
rkind = asindices(rhdr, rkey)
# construct functions to extract key values from left table
lgetk = operator.itemgetter(*lkind)
# determine indices of non-key fields in the right table
# (in the output, we only include key fields from the left table - we
# don't want to duplicate fields)
rvind = [i for i in range(len(rhdr)) if i not in rkind]
rgetv = rowgetter(*rvind)
# determine the output fields
if lprefix is None:
outhdr = list(lhdr)
else:
outhdr = [(text_type(lprefix) + text_type(f)) for f in lhdr]
if rprefix is None:
outhdr.extend(rgetv(rhdr))
else:
outhdr.extend([(text_type(rprefix) + text_type(f))
for f in rgetv(rhdr)])
yield tuple(outhdr)
# define a function to join rows
def joinrows(_lrow, _rrow):
# start with the left row
_outrow = list(_lrow)
# extend with non-key values from the right row
_outrow.extend(rgetv(_rrow))
return tuple(_outrow)
for lrow in lit:
k = lgetk(lrow)
if k in rlookup:
rrow = rlookup[k]
yield joinrows(lrow, rrow)
else:
outrow = list(lrow) # start with the left row
# extend with missing values in place of the right row
outrow.extend([missing] * len(rvind))
yield tuple(outrow)
def test_lookupone():
t1 = (('foo', 'bar'), ('a', 1), ('b', 2), ('b', 3))
# lookup one column on another under strict mode
try:
lookupone(t1, 'foo', 'bar', strict=True)
except DuplicateKeyError:
pass # expected
else:
assert False, 'expected error'
# lookup one column on another under, not strict
actual = lookupone(t1, 'foo', 'bar', strict=False)
expect = {'a': 1, 'b': 2} # first value wins
eq_(expect, actual)
# test default value - tuple of whole row
actual = lookupone(t1, 'foo', strict=False) # no value selector
expect = {'a': ('a', 1), 'b': ('b', 2)} # first wins
eq_(expect, actual)
t2 = (('foo', 'bar', 'baz'),
('a', 1, True),
('b', 2, False),
('b', 3, True),
('b', 3, False))
# test value selection
actual = lookupone(t2, 'foo', ('bar', 'baz'), strict=False)
expect = {'a': (1, True), 'b': (2, False)}
eq_(expect, actual)
# test compound key
actual = lookupone(t2, ('foo', 'bar'), 'baz', strict=False)
expect = {('a', 1): True, ('b', 2): False, ('b', 3): True} # first wins
eq_(expect, actual)
