boltons/tests/test_iterutils.py

505 lines
15 KiB
Python

import os
import pytest
from boltons.dictutils import OMD
from boltons.iterutils import (first,
remap,
research,
default_enter,
default_exit,
get_path)
from boltons.namedutils import namedtuple
CUR_PATH = os.path.abspath(__file__)
isbool = lambda x: isinstance(x, bool)
isint = lambda x: isinstance(x, int)
odd = lambda x: isint(x) and x % 2 != 0
even = lambda x: isint(x) and x % 2 == 0
is_meaning_of_life = lambda x: x == 42
class TestFirst(object):
def test_empty_iterables(self):
"""
Empty iterables return None.
"""
s = set()
l = []
assert first(s) is None
assert first(l) is None
def test_default_value(self):
"""
Empty iterables + a default value return the default value.
"""
s = set()
l = []
assert first(s, default=42) == 42
assert first(l, default=3.14) == 3.14
l = [0, False, []]
assert first(l, default=3.14) == 3.14
def test_selection(self):
"""
Success cases with and without a key function.
"""
l = [(), 0, False, 3, []]
assert first(l, default=42) == 3
assert first(l, key=isint) == 0
assert first(l, key=isbool) is False
assert first(l, key=odd) == 3
assert first(l, key=even) == 0
assert first(l, key=is_meaning_of_life) is None
class TestRemap(object):
# TODO: test namedtuples and other immutable containers
def test_basic_clone(self):
orig = {"a": "b", "c": [1, 2]}
assert orig == remap(orig)
orig2 = [{1: 2}, {"a": "b", "c": [1, 2, {"cat": "dog"}]}]
assert orig2 == remap(orig2)
def test_empty(self):
assert [] == remap([])
assert {} == remap({})
assert set() == remap(set())
def test_unremappable(self):
obj = object()
with pytest.raises(TypeError):
remap(obj)
def test_basic_upper(self):
orig = {'a': 1, 'b': object(), 'c': {'d': set()}}
remapped = remap(orig, lambda p, k, v: (k.upper(), v))
assert orig['a'] == remapped['A']
assert orig['b'] == remapped['B']
assert orig['c']['d'] == remapped['C']['D']
def test_item_drop(self):
orig = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
even_items = remap(orig, lambda p, k, v: not (v % 2))
assert even_items == [0, 2, 4, 6, 8]
def test_noncallables(self):
with pytest.raises(TypeError):
remap([], visit='test')
with pytest.raises(TypeError):
remap([], enter='test')
with pytest.raises(TypeError):
remap([], exit='test')
def test_sub_selfref(self):
coll = [0, 1, 2, 3]
sub = []
sub.append(sub)
coll.append(sub)
with pytest.raises(RuntimeError):
# if equal, should recurse infinitely
assert coll == remap(coll)
def test_root_selfref(self):
selfref = [0, 1, 2, 3]
selfref.append(selfref)
with pytest.raises(RuntimeError):
assert selfref == remap(selfref)
selfref2 = {}
selfref2['self'] = selfref2
with pytest.raises(RuntimeError):
assert selfref2 == remap(selfref2)
def test_duperef(self):
val = ['hello']
duperef = [val, val]
remapped = remap(duperef)
assert remapped[0] is remapped[1]
assert remapped[0] is not duperef[0]
def test_namedtuple(self):
"""TODO: this fails right now because namedtuples' __new__ is
overridden to accept arguments. remap's default_enter tries
to create an empty namedtuple and gets a TypeError.
Could make it so that immutable types actually don't create a
blank new parent and instead use the old_parent as a
placeholder, creating a new one at exit-time from the value's
__class__ (how default_exit works now). But even then it would
have to *args in the values, as namedtuple constructors don't
take an iterable.
"""
Point = namedtuple('Point', 'x y')
point_map = {'origin': [Point(0, 0)]}
with pytest.raises(TypeError):
remapped = remap(point_map)
assert isinstance(remapped['origin'][0], Point)
def test_path(self):
path_map = {}
# test visit's path
target_str = 'test'
orig = [[[target_str]]]
ref_path = (0, 0, 0)
def visit(path, key, value):
if value is target_str:
path_map['target_str'] = path + (key,)
return key, value
remapped = remap(orig, visit=visit)
assert remapped == orig
assert path_map['target_str'] == ref_path
# test enter's path
target_obj = object()
orig = {'a': {'b': {'c': {'d': ['e', target_obj, 'f']}}}}
ref_path = ('a', 'b', 'c', 'd', 1)
def enter(path, key, value):
if value is target_obj:
path_map['target_obj'] = path + (key,)
return default_enter(path, key, value)
remapped = remap(orig, enter=enter)
assert remapped == orig
assert path_map['target_obj'] == ref_path
# test exit's path
target_set = frozenset([1, 7, 3, 8])
orig = [0, 1, 2, [3, 4, [5, target_set]]]
ref_path = (3, 2, 1)
def exit(path, key, old_parent, new_parent, new_items):
if old_parent is target_set:
path_map['target_set'] = path + (key,)
return default_exit(path, key, old_parent, new_parent, new_items)
remapped = remap(orig, exit=exit)
assert remapped == orig
assert path_map['target_set'] == ref_path
def test_reraise_visit(self):
root = {'A': 'b', 1: 2}
key_to_lower = lambda p, k, v: (k.lower(), v)
with pytest.raises(AttributeError):
remap(root, key_to_lower)
remapped = remap(root, key_to_lower, reraise_visit=False)
assert remapped['a'] == 'b'
assert remapped[1] == 2
def test_drop_nones(self):
orig = {'a': 1, 'b': None, 'c': [3, None, 4, None]}
ref = {'a': 1, 'c': [3, 4]}
drop_none = lambda p, k, v: v is not None
remapped = remap(orig, visit=drop_none)
assert remapped == ref
orig = [None] * 100
remapped = remap(orig, drop_none)
assert not remapped
def test_dict_to_omd(self):
def enter(path, key, value):
if isinstance(value, dict):
return OMD(), sorted(value.items())
return default_enter(path, key, value)
orig = [{'title': 'Wild Palms',
'ratings': {1: 1, 2: 3, 3: 5, 4: 6, 5: 3}},
{'title': 'Twin Peaks',
'ratings': {1: 3, 2: 2, 3: 8, 4: 12, 5: 15}}]
remapped = remap(orig, enter=enter)
assert remapped == orig
assert isinstance(remapped[0], OMD)
assert isinstance(remapped[0]['ratings'], OMD)
assert isinstance(remapped[1], OMD)
assert isinstance(remapped[1]['ratings'], OMD)
def test_sort_all_lists(self):
def exit(path, key, old_parent, new_parent, new_items):
# NB: in this case, I'd normally use *a, **kw
ret = default_exit(path, key, old_parent, new_parent, new_items)
if isinstance(ret, list):
ret.sort()
return ret
# NB: Airplane model numbers (Boeing and Airbus)
orig = [[[7, 0, 7],
[7, 2, 7],
[7, 7, 7],
[7, 3, 7]],
[[3, 8, 0],
[3, 2, 0],
[3, 1, 9],
[3, 5, 0]]]
ref = [[[0, 2, 3],
[0, 3, 5],
[0, 3, 8],
[1, 3, 9]],
[[0, 7, 7],
[2, 7, 7],
[3, 7, 7],
[7, 7, 7]]]
remapped = remap(orig, exit=exit)
assert remapped == ref
def test_collector_pattern(self):
all_interests = set()
def enter(path, key, value):
try:
all_interests.update(value['interests'])
except:
pass
return default_enter(path, key, value)
orig = [{'name': 'Kate',
'interests': ['theater', 'manga'],
'dads': [{'name': 'Chris',
'interests': ['biking', 'python']}]},
{'name': 'Avery',
'interests': ['museums', 'pears'],
'dads': [{'name': 'Kurt',
'interests': ['python', 'recursion']}]}]
ref = set(['python', 'recursion', 'biking', 'museums',
'pears', 'theater', 'manga'])
remap(orig, enter=enter)
assert all_interests == ref
def test_add_length(self):
def exit(path, key, old_parent, new_parent, new_items):
ret = default_exit(path, key, old_parent, new_parent, new_items)
try:
ret['review_length'] = len(ret['review'])
except:
pass
return ret
orig = {'Star Trek':
{'TNG': {'stars': 10,
'review': "Episodic AND deep. <3 Data."},
'DS9': {'stars': 8.5,
'review': "Like TNG, but with a story and no Data."},
'ENT': {'stars': None,
'review': "Can't review what you can't watch."}},
'Babylon 5': {'stars': 6,
'review': "Sophomoric, like a bitter laugh."},
'Dr. Who': {'stars': None,
'review': "800 episodes is too many to review."}}
remapped = remap(orig, exit=exit)
assert (remapped['Star Trek']['TNG']['review_length']
< remapped['Star Trek']['DS9']['review_length'])
def test_prepop(self):
"""Demonstrating normalization and ID addition through prepopulating
the objects with an enter callback.
"""
base_obj = {'name': None,
'rank': None,
'id': 1}
def enter(path, key, value):
new_parent, new_items = default_enter(path, key, value)
try:
new_parent.update(base_obj)
base_obj['id'] += 1
except:
pass
return new_parent, new_items
orig = [{'name': 'Firefox', 'rank': 1},
{'name': 'Chrome', 'rank': 2},
{'name': 'IE'}]
ref = [{'name': 'Firefox', 'rank': 1, 'id': 1},
{'name': 'Chrome', 'rank': 2, 'id': 2},
{'name': 'IE', 'rank': None, 'id': 3}]
remapped = remap(orig, enter=enter)
assert remapped == ref
def test_remap_set(self):
# explicit test for sets to make sure #84 is covered
s = set([1, 2, 3])
assert remap(s) == s
fs = frozenset([1, 2, 3])
assert remap(fs) == fs
def test_remap_file(self):
with open(CUR_PATH, 'rb') as f:
x = {'a': [1, 2, 3], 'f': [f]}
assert remap(x) == x
f.read()
assert remap(x) == x
f.close() # see #146
assert remap(x) == x
return
class TestGetPath(object):
def test_depth_one(self):
root = ['test']
assert get_path(root, (0,)) == 'test'
assert get_path(root, '0') == 'test'
root = {'key': 'value'}
assert get_path(root, ('key',)) == 'value'
assert get_path(root, 'key') == 'value'
def test_depth_two(self):
root = {'key': ['test']}
assert get_path(root, ('key', 0)) == 'test'
assert get_path(root, 'key.0') == 'test'
def test_research():
root = {}
with pytest.raises(TypeError):
research(root, query=None)
root = {'a': 'a'}
res = research(root, query=lambda p, k, v: v == 'a')
assert len(res) == 1
assert res[0] == (('a',), 'a')
def broken_query(p, k, v):
raise RuntimeError()
with pytest.raises(RuntimeError):
research(root, broken_query, reraise=True)
# empty results with default, reraise=False
assert research(root, broken_query) == []
def test_backoff_basic():
from boltons.iterutils import backoff
assert backoff(1, 16) == [1.0, 2.0, 4.0, 8.0, 16.0]
assert backoff(1, 1) == [1.0]
assert backoff(2, 15) == [2.0, 4.0, 8.0, 15.0]
def test_backoff_repeat():
from boltons.iterutils import backoff_iter
fives = []
for val in backoff_iter(5, 5, count='repeat'):
fives.append(val)
if len(fives) >= 1000:
break
assert fives == [5] * 1000
def test_backoff_zero_start():
from boltons.iterutils import backoff
assert backoff(0, 16) == [0.0, 1.0, 2.0, 4.0, 8.0, 16.0]
assert backoff(0, 15) == [0.0, 1.0, 2.0, 4.0, 8.0, 15.0]
slow_backoff = [round(x, 2) for x in backoff(0, 2.9, factor=1.2)]
assert slow_backoff == [0.0, 1.0, 1.2, 1.44, 1.73, 2.07, 2.49, 2.9]
def test_backoff_validation():
from boltons.iterutils import backoff
with pytest.raises(ValueError):
backoff(8, 2)
with pytest.raises(ValueError):
backoff(1, 0)
with pytest.raises(ValueError):
backoff(-1, 10)
with pytest.raises(ValueError):
backoff(2, 8, factor=0)
with pytest.raises(ValueError):
backoff(2, 8, jitter=20)
def test_backoff_jitter():
from boltons.iterutils import backoff
start, stop = 1, 256
unjittered = backoff(start, stop)
jittered = backoff(start, stop, jitter=True)
assert len(unjittered) == len(jittered)
assert [u >= j for u, j in zip(unjittered, jittered)]
neg_jittered = backoff(start, stop, jitter=-0.01)
assert len(unjittered) == len(neg_jittered)
assert [u <= j for u, j in zip(unjittered, neg_jittered)]
o_jittered = backoff(start, stop, jitter=-0.0)
assert len(unjittered) == len(o_jittered)
assert [u == j for u, j in zip(unjittered, o_jittered)]
nonconst_jittered = backoff(stop, stop, count=5, jitter=True)
assert len(nonconst_jittered) == 5
# no two should be equal realistically
assert len(set(nonconst_jittered)) == 5
def test_guiderator():
import string
from boltons.iterutils import GUIDerator
guid_iter = GUIDerator()
guid = next(guid_iter)
assert guid
assert len(guid) == guid_iter.size
assert all([c in string.hexdigits for c in guid])
guid2 = next(guid_iter)
assert guid != guid2
# custom size
guid_iter = GUIDerator(size=26)
assert len(next(guid_iter)) == 26
def test_seqguiderator():
import string
from boltons.iterutils import SequentialGUIDerator as GUIDerator
guid_iter = GUIDerator()
guid = next(guid_iter)
assert guid
assert len(guid) == guid_iter.size
assert all([c in string.hexdigits for c in guid])
guid2 = next(guid_iter)
assert guid != guid2
# custom size
for x in range(10000):
guid_iter = GUIDerator(size=26)
assert len(next(guid_iter)) == 26