84 lines
No EOL
2.3 KiB
Python
84 lines
No EOL
2.3 KiB
Python
import re
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BYTE = 1
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KIBIBYTE = 1024 * BYTE
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MIBIBYTE = 1024 * KIBIBYTE
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GIBIBYTE = 1024 * MIBIBYTE
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TEBIBYTE = 1024 * GIBIBYTE
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PEBIBYTE = 1024 * TEBIBYTE
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EXIBYTE = 1024 * PEBIBYTE
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ZEBIBYTE = 1024 * EXIBYTE
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YOBIBYTE = 1024 * ZEBIBYTE
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UNIT_STRINGS = {
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BYTE: 'b',
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KIBIBYTE: 'KiB',
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MIBIBYTE: 'MiB',
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GIBIBYTE: 'GiB',
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TEBIBYTE: 'TiB',
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PEBIBYTE: 'PiB',
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EXIBYTE: 'EiB',
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ZEBIBYTE: 'ZiB',
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YOBIBYTE: 'YiB',
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}
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UNITS_SORTED = sorted(UNIT_STRINGS.keys(), reverse=True)
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def bytestring(size, force_unit=None):
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'''
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Convert a number into a binary-standard string.
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force_unit:
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If None, an appropriate size unit is chosen automatically.
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Otherwise, you can provide one of the size constants to force that divisor.
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'''
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if force_unit is None:
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divisor = get_appropriate_divisor(size)
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else:
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divisor = force_unit
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size_unit_string = UNIT_STRINGS[divisor]
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size_string = '%.3f %s' % ((size / divisor), size_unit_string)
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return size_string
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def get_appropriate_divisor(size):
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size = abs(size)
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for unit in UNITS_SORTED:
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if size >= unit:
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appropriate_unit = unit
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break
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else:
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appropriate_unit = 1
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return appropriate_unit
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def parsebytes(string):
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'''
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Given a string like "100 kib", return the appropriate integer value.
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'''
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string = string.lower().strip().replace(' ', '')
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matches = re.findall('((\\.|-|\\d)+)', string)
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if len(matches) == 0:
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raise ValueError('No numbers found')
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if len(matches) > 1:
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raise ValueError('Too many numbers found')
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byte_value = matches[0][0]
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if not string.startswith(byte_value):
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raise ValueError('Number is not at start of string')
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# if the string has no text besides the number, just return that int.
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string = string.replace(byte_value, '')
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byte_value = float(byte_value)
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if string == '':
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return int(byte_value)
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reversed_units = {value.lower():key for (key, value) in UNIT_STRINGS.items()}
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for (unit_string, multiplier) in reversed_units.items():
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# accept kib, k, kb
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if string in (unit_string, unit_string[0], unit_string.replace('i', '')):
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break
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else:
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raise ValueError('Could not determine byte value of %s' % string)
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return int(byte_value * multiplier) |