monty 0.0.21

A sandboxed, snapshotable Python interpreter written in Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159

# === dict.clear() ===
d = {'a': 1, 'b': 2}
d.clear()
assert d == {}

d = {}
d.clear()
assert d == {}

# === dict.copy() ===
d = {'a': 1, 'b': 2}
copy = d.copy()
assert copy == {'a': 1, 'b': 2}
assert copy is not d
d['c'] = 3
assert 'c' not in copy

d = {}
copy = d.copy()
assert copy == {}

# === dict.update() ===
d = {'a': 1}
d.update({'b': 2})
assert d == {'a': 1, 'b': 2}

d = {'a': 1}
d.update({'a': 10})
assert d == {'a': 10}

d = {'a': 1}
d.update()
assert d == {'a': 1}

d = {}
d.update([('a', 1), ('b', 2)])
assert d == {'a': 1, 'b': 2}

# === dict.setdefault() ===
d = {'a': 1}
result = d.setdefault('a', 10)
assert result == 1
assert d == {'a': 1}

d = {'a': 1}
result = d.setdefault('b', 2)
assert result == 2
assert d == {'a': 1, 'b': 2}

d = {'a': 1}
result = d.setdefault('b')
assert result is None
assert d == {'a': 1, 'b': None}

# === dict.popitem() ===
d = {'a': 1, 'b': 2}
item = d.popitem()
assert item == ('b', 2)
assert d == {'a': 1}

d = {'x': 10}
item = d.popitem()
assert item == ('x', 10)
assert d == {}

# === dict.fromkeys() ===
d = dict.fromkeys(['a', 'b', 'c'])
assert d == {'a': None, 'b': None, 'c': None}

d = dict.fromkeys(['a', 'b'], 0)
assert d == {'a': 0, 'b': 0}

d = dict.fromkeys([])
assert d == {}

d = dict.fromkeys('abc')
assert d == {'a': None, 'b': None, 'c': None}

d = dict.fromkeys(range(3), 'x')
assert d == {0: 'x', 1: 'x', 2: 'x'}

d = dict.fromkeys((1, 2, 3), [])
assert d[1] is d[2] and d[2] is d[3], 'fromkeys shares same value object for all keys'

# Duplicate keys - later occurrence wins
d = dict.fromkeys(['a', 'b', 'a'], 1)
assert d == {'a': 1, 'b': 1}
assert list(d.keys()) == ['a', 'b']

# === dict.fromkeys() instance access ===
# fromkeys is a classmethod but should also work on instances
d = {}.fromkeys(['a', 'b'])
assert d == {'a': None, 'b': None}

d = {'x': 1}.fromkeys(['a', 'b'], 0)
assert d == {'a': 0, 'b': 0}

# === dict.update() with keyword arguments ===
d = {'a': 1}
d.update(b=2)
assert d == {'a': 1, 'b': 2}

d = {'a': 1}
d.update(b=2, c=3)
assert d == {'a': 1, 'b': 2, 'c': 3}

d = {'a': 1}
d.update(a=10)
assert d == {'a': 10}

d = {}
d.update(a=1, b=2)
assert d == {'a': 1, 'b': 2}

# update with both positional dict and kwargs
d = {'a': 1}
d.update({'b': 2}, c=3)
assert d == {'a': 1, 'b': 2, 'c': 3}

# kwargs overwrite positional dict values
d = {'a': 1}
d.update({'b': 2}, b=20)
assert d == {'a': 1, 'b': 20}

# update with iterable and kwargs
d = {}
d.update([('a', 1)], b=2)
assert d == {'a': 1, 'b': 2}

# `**` unpacking with a runtime-built (non-interned) string key must still
# reach **kwargs — only genuinely non-string keys are rejected.
runtime_key = 'zzz' + 'qqq'
d = dict(**{runtime_key: 1})
assert d == {'zzzqqq': 1}
d.update(**{runtime_key: 2})
assert d == {'zzzqqq': 2}

# === Error message for unknown classmethod ===
# Error message should say 'dict' not 'type'
try:
    dict.nonexistent()
    assert False, 'should raise AttributeError'
except AttributeError as e:
    msg = str(e)
    assert 'dict' in msg, f'error should mention dict, got: {e}'
    assert 'nonexistent' in msg, f'error should mention method name, got: {e}'

# === dict.update() sequence element error ===
# Invalid sequence elements should raise ValueError
try:
    d = {}
    d.update([('a', 1), 'x', ('c', 3)])  # 'x' at index 1 is not a 2-tuple
    assert False, 'should raise ValueError'
except (ValueError, TypeError) as e:
    msg = str(e)
    # Error message should mention 'length' requirement
    assert 'length' in msg.lower(), f'error should mention length, got: {e}'
    # TODO: CPython includes element index (#N) in error message
    # assert '#1' in msg, 'error should mention element index'