Turns out PHP standard crc32 method is non-standard (while crc32b is).
Here is how to implement it in Python:

def php_crc32(a):
    '''
    References:
    - https://www.php.net/manual/en/function.hash-file.php#104836
    - https://stackoverflow.com/a/50843127/636849
    '''
    crc = 0xffffffff
    for x in a:
        crc ^= x << 24;
        for k in range(8):
            crc = (crc << 1) ^ 0x04c11db7 if crc & 0x80000000 else crc << 1
    crc = ~crc
    crc &= 0xffffffff
    # Convert from big endian to little endian:
    return int.from_bytes(crc.to_bytes(4, 'big'), 'little')