bytes / kb / mb / gb / tb / etc unit converter

byteunits.py

# BY ULTRAFUNKAMSTERDAM 
# https://github.com/ultrafunkamsterdam

"""

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     ██ ██ ██  ██  ██ ██      ██      ██               ██    ██    ██    ██ ██      ██
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  _           _         _   _ _ _
 | |__  _   _| |_   ___| |_(_) | |
 | '_ \| | | | __| / __| __| | | |
 | |_) | |_| | |_  \__ \ |_| | | |
 |_.__/ \__,_|\__| |___/\__|_|_|_|   _             _
 | |__   __ ___   _____  | |_ ___   | | ___   ___ | | __  _   _ _ __
 | '_ \ / _` \ \ / / _ \ | __/ _ \  | |/ _ \ / _ \| |/ / | | | | '_ \
 | | | | (_| |\ V /  __/ | || (_) | | | (_) | (_) |   <  | |_| | |_) |
 |_| |_|\__,_| \_/ \___|  \__\___/_ |_|\___/ \___/|_|\_\  \__,_| .__/
   _____   _____ _ __ _   _  | |_(_)_ __ ___   ___             |_|
  / _ \ \ / / _ \ '__| | | | | __| | '_ ` _ \ / _ \
 |  __/\ V /  __/ |  | |_| | | |_| | | | | | |  __/
  \___| \_/ \___|_|   \__, |  \__|_|_| |_|_|_|\___|
  _   _  ___  _   _   |___/  ___  ___  __| | (_) |_
 | | | |/ _ \| | | | | '_ \ / _ \/ _ \/ _` | | | __|
 | |_| | (_) | |_| | | | | |  __/  __/ (_| | | | |_
  \__, |\___/ \__,_| |_| |_|\___|\___|\__,_| |_|\__|
  |___/

"""


def convert_unit( num , src_unit: str = "b" , dst_unit: str = "mb" , human_format = False ):
    """
    convert the given <num>  from <src_unit> value to <dst_unit> value

    possible unit values (lower case also accepted!)
    "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"

    usage
    -----
    >>> convert_unit(3235432423, "b", "mb")
    3085.548804283142


    when only dst_unit is provided, we assume the source is bytes
    ---
    >>> convert_unit(13235432423, dst_unit="MB")
    3085.548804283142


    you can pass the units as positionals as well
    ---
    >>> convert_unit(4, "GB", "MB")
    4096
    
    
    if you want to print a "human friendly string"
    ---
    >>> convert_unit(13235432423, dst_unit="mb", human_format = True)
    '12622.29 MB'

    """
    src_unit = src_unit.upper()
    dst_unit = dst_unit.upper()
    unames = ("B" , "KB" , "MB" , "GB" , "TB" , "PB" , "EB" , "ZB" , "YB")
    err = None
    if src_unit not in unames:
        err = "unit from" , src_unit
    if dst_unit not in unames:
        err = "unit to" , dst_unit
    if err:
        raise ValueError( "your %s = %s but should be one of %s" % (*err , unames) )
    idxfrom = unames.index( src_unit )
    idxto = unames.index( dst_unit )
    ret = None
    if src_unit == dst_unit:
        ret = num
    if idxfrom < idxto:
        ret = num / (1024 ** (idxto - idxfrom))
    if idxfrom > idxto:
        ret = num * (1024 ** (idxfrom - idxto))
    
    if human_format:
        ret = "{0:.2f} {1}".format( ret , dst_unit )
    return ret