diff options
| -rw-r--r-- | numpy/core/_exceptions.py | 52 | ||||
| -rw-r--r-- | numpy/core/tests/test__exceptions.py | 42 |
2 files changed, 92 insertions, 2 deletions
diff --git a/numpy/core/_exceptions.py b/numpy/core/_exceptions.py index a1af7a78d..6e658a9b8 100644 --- a/numpy/core/_exceptions.py +++ b/numpy/core/_exceptions.py @@ -146,6 +146,54 @@ class _ArrayMemoryError(MemoryError): self.shape = shape self.dtype = dtype - def __str__(self): - return "Unable to allocate array with shape {} and data type {}".format(self.shape, self.dtype) + @property + def _total_size(self): + num_bytes = self.dtype.itemsize + for dim in self.shape: + num_bytes *= dim + return num_bytes + + @staticmethod + def _size_to_string(num_bytes): + """ Convert a number of bytes into a binary size string """ + import math + + # https://en.wikipedia.org/wiki/Binary_prefix + LOG2_STEP = 10 + STEP = 1024 + units = ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB'] + + unit_i = max(num_bytes.bit_length() - 1, 1) // LOG2_STEP + unit_val = 1 << (unit_i * LOG2_STEP) + n_units = num_bytes / unit_val + del unit_val + + # ensure we pick a unit that is correct after rounding + if round(n_units) == STEP: + unit_i += 1 + n_units /= STEP + + # deal with sizes so large that we don't have units for them + if unit_i >= len(units): + new_unit_i = len(units) - 1 + n_units *= 1 << ((unit_i - new_unit_i) * LOG2_STEP) + unit_i = new_unit_i + + unit_name = units[unit_i] + # format with a sensible number of digits + if unit_i == 0: + # no decimal point on bytes + return '{:.0f} {}'.format(n_units, unit_name) + elif round(n_units) < 1000: + # 3 significant figures, if none are dropped to the left of the . + return '{:#.3g} {}'.format(n_units, unit_name) + else: + # just give all the digits otherwise + return '{:#.0f} {}'.format(n_units, unit_name) + def __str__(self): + size_str = self._size_to_string(self._total_size) + return ( + "Unable to allocate {} for an array with shape {} and data type {}" + .format(size_str, self.shape, self.dtype) + ) diff --git a/numpy/core/tests/test__exceptions.py b/numpy/core/tests/test__exceptions.py new file mode 100644 index 000000000..494b51f34 --- /dev/null +++ b/numpy/core/tests/test__exceptions.py @@ -0,0 +1,42 @@ +""" +Tests of the ._exceptions module. Primarily for exercising the __str__ methods. +""" +import numpy as np + +_ArrayMemoryError = np.core._exceptions._ArrayMemoryError + +class TestArrayMemoryError: + def test_str(self): + e = _ArrayMemoryError((1023,), np.dtype(np.uint8)) + str(e) # not crashing is enough + + # testing these properties is easier than testing the full string repr + def test__size_to_string(self): + """ Test e._size_to_string """ + f = _ArrayMemoryError._size_to_string + Ki = 1024 + assert f(0) == '0 bytes' + assert f(1) == '1 bytes' + assert f(1023) == '1023 bytes' + assert f(Ki) == '1.00 KiB' + assert f(Ki+1) == '1.00 KiB' + assert f(10*Ki) == '10.0 KiB' + assert f(int(999.4*Ki)) == '999. KiB' + assert f(int(1023.4*Ki)) == '1023. KiB' + assert f(int(1023.5*Ki)) == '1.00 MiB' + assert f(Ki*Ki) == '1.00 MiB' + + # 1023.9999 Mib should round to 1 GiB + assert f(int(Ki*Ki*Ki*0.9999)) == '1.00 GiB' + assert f(Ki*Ki*Ki*Ki*Ki*Ki) == '1.00 EiB' + # larger than sys.maxsize, adding larger prefices isn't going to help + # anyway. + assert f(Ki*Ki*Ki*Ki*Ki*Ki*123456) == '123456. EiB' + + def test__total_size(self): + """ Test e._total_size """ + e = _ArrayMemoryError((1,), np.dtype(np.uint8)) + assert e._total_size == 1 + + e = _ArrayMemoryError((2, 4), np.dtype((np.uint64, 16))) + assert e._total_size == 1024 |