forked from Rust-related/RustPython
80 lines
2.0 KiB
Python
80 lines
2.0 KiB
Python
from functools import reduce
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from testutils import assert_raises
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class Squares:
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def __init__(self, max):
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self.max = max
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self.sofar = []
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def __len__(self):
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return len(self.sofar)
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def __getitem__(self, i):
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if not 0 <= i < self.max: raise IndexError
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n = len(self.sofar)
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while n <= i:
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self.sofar.append(n*n)
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n += 1
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return self.sofar[i]
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def add(a, b):
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return a + b
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assert reduce(add, ['a', 'b', 'c']) == 'abc'
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assert reduce(add, ['a', 'b', 'c'], str(42)) == '42abc'
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assert reduce(add, [['a', 'c'], [], ['d', 'w']], []) == ['a','c','d','w']
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assert reduce(add, [['a', 'c'], [], ['d', 'w']], []) == ['a','c','d','w']
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assert reduce(lambda x, y: x*y, range(2, 21), 1) == 2432902008176640000
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assert reduce(add, Squares(10)) == 285
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assert reduce(add, Squares(10), 0) == 285
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assert reduce(add, Squares(0), 0) == 0
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assert reduce(42, "1") == "1"
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assert reduce(42, "", "1") == "1"
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with assert_raises(TypeError):
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reduce()
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with assert_raises(TypeError):
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reduce(42, 42)
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with assert_raises(TypeError):
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reduce(42, 42, 42)
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class TestFailingIter:
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def __iter__(self):
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raise RuntimeError
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with assert_raises(RuntimeError):
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reduce(add, TestFailingIter())
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assert reduce(add, [], None) == None
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assert reduce(add, [], 42) == 42
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class BadSeq:
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def __getitem__(self, index):
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raise ValueError
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with assert_raises(ValueError):
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reduce(42, BadSeq())
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# Test reduce()'s use of iterators.
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class SequenceClass:
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def __init__(self, n):
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self.n = n
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def __getitem__(self, i):
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if 0 <= i < self.n:
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return i
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else:
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raise IndexError
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assert reduce(add, SequenceClass(5)) == 10
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assert reduce(add, SequenceClass(5), 42) == 52
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with assert_raises(TypeError):
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reduce(add, SequenceClass(0))
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assert reduce(add, SequenceClass(0), 42) == 42
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assert reduce(add, SequenceClass(1)) == 0
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assert reduce(add, SequenceClass(1), 42) == 42
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d = {"one": 1, "two": 2, "three": 3}
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assert reduce(add, d) == "".join(d.keys())
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