[IDA Pro][python Script] :: How to Export binary pattern of an address up to it is end?

This is far from being error-proof but here's a possible start:

from __future__ import print_function

def dump_instruction_opcodes(start, end):
    opcodes = list()
    for ea in xrange(start, end):
        opcodes.append(idaapi.idaapi.get_original_byte(ea))

    return opcodes

def main():
    # get cursor position
    screen_ea = ScreenEA()

    func = idaapi.get_func(screen_ea)
    if not func:
        print("No function at address {:#x}".format(screen_ea))
        return
    elif not func.does_return:
        print("Function doesn't have an exit point...")
        return
    func_start = func.startEA
    func_end = func.endEA    
    func_name = GetFunctionName(func_start)

    print("Function '{}' starts at {:#x} and ends at {:#x}".format(func_name, func_start, func_end))

    # traverse code or data in function boundaries
    for head in Heads(func_start, func_end):
        # we just want code, not data
        if isCode(GetFlags(head)):
            next_head = NextHead(head, func_end)
            #if last instruction, set end to func_end
            if next_head == BADADDR:
                next_head = func_end
            #print("Current inst: {:#x}, next inst: {:#x}".format(head, next_head))
            opcodes = dump_instruction_opcodes(head, next_head)
            printable_opcodes = ["{:02x}".format(op) for op in opcodes]
            print("Current inst: {:#x} [{}]".format(head, ' '.join(printable_opcodes)))

    print("[*] Done!")

if __name__ == "__main__":
    main()

Example

Input:

.text:0040F120 sub_40F120 proc near         ; CODE XREF: sub_40A8E0+2Dp
.text:0040F120
.text:0040F120 arg_0           = dword ptr  8
.text:0040F120
.text:0040F120                 push    ebp
.text:0040F121                 mov     ebp, esp
.text:0040F123                 push    esi
.text:0040F124                 mov     esi, [ebp+arg_0]
.text:0040F127                 test    esi, esi
.text:0040F129                 jnz     short loc_40F133
.text:0040F12B
.text:0040F12B loc_40F12B:                             ; CODE XREF: 40F120+1Ej
.text:0040F12B                                         ; 40F120+28j
.text:0040F12B                 mov     eax, 0FFFFFFFEh
...

Output:

Function 'sub_40F120' starts at 0x40f120 and ends at 0x40f180
Current inst: 0x40f120 [55]
Current inst: 0x40f121 [8b ec]
Current inst: 0x40f123 [56]
Current inst: 0x40f124 [8b 75 08]
Current inst: 0x40f127 [85 f6]
Current inst: 0x40f129 [75 08]
Current inst: 0x40f12b [b8 fe ff ff ff]
...

The above script will work most of the time, but there can be multiple problems, including:

• function has thunk(s) [you'll need to check if inst is a flow instruction and check if target is within function bounds or not]
• One of the exit point(s) disrupt the CFG (syscall , int, etc.) [you'll need to trackback...]
• Function has inner calls