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All the solutions I found were for lists.
Thanks.
885
To find the length of a bytes object in Python, call len() builtin function and pass the bytes object as argument. len() function returns the number of bytes in the object.
python3's bytes and bytearray classes both hold arrays of bytes, where each byte can take on a value between 0 and 255. The primary difference is that a bytes object is immutable, meaning that once created, you cannot modify its elements. By contrast, a bytearray object allows you to modify its elements.
This will give you 100 zero bytes:
bytearray(100) Or filling the array with non zero values:
bytearray([1] * 100) For bytes, one may also use the literal form b'\0' * 100.
# Python 3.6.4 (64-bit), Windows 10 from timeit import timeit print(timeit(r'b"\0" * 100')) # 0.04987576772443264 print(timeit('bytes(100)')) # 0.1353608166305015 Update1: With constant folding in Python 3.7, the literal from is now almost 20 times faster.
Update2: Apparently constant folding has a limit:
>>> from dis import dis >>> dis(r'b"\0" * 4096') 1 0 LOAD_CONST 0 (b'\x00\x00\x00...') 2 RETURN_VALUE >>> dis(r'b"\0" * 4097') 1 0 LOAD_CONST 0 (b'\x00') 2 LOAD_CONST 1 (4097) 4 BINARY_MULTIPLY 6 RETURN_VALUE If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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