Brainfuck interpreter written in Python.

Brainfuck.py

## Brainfuck.py by pzp1997 (May 11, 2014)
## Written in Python 3.4.0

def interpreter(program, userInput):
    array = [0]*30000
    pointer = 0
    pc = 0
    nest = 1

    while pc < len(program):
        if program[pc] == ">":
            if pointer + 1 == len(array):
                array.append(0)
            pointer += 1
        elif program[pc] == "<":
            pointer -= 1
        elif program[pc] == "+":
            array[pointer] += 1
        elif program[pc] == "-":
            array[pointer] -= 1
        elif program[pc] == ".":
            print(chr(array[pointer]), end="")
        elif program[pc] == ",":
            try:
                array[pointer] = ord(userInput[0])
                userInput = userInput[1:]
            except IndexError:
                break
        elif program[pc] == "[":
            if array[pointer] == 0:
                while pc < len(program):
                    pc += 1
                    if program[pc] == "]":
                        nest -= 1
                    elif program[pc] == "[":
                        nest += 1
                    if nest == 0:
                        nest = 1
                        break
        elif program[pc] == "]":
            if array[pointer] != 0:
                while pc > 0:
                    pc -= 1
                    if program[pc] == "]":
                        nest += 1
                    elif program[pc] == "[":
                        nest -= 1
                    if nest == 0:
                        nest = 1
                        break
        pc += 1

def main():
    print("Brainfuck.py by pzp1997 (May 11, 2014)")
    print("Written in Python 3.4.0")
    print()

    while True:
        code = input()
        if "," in code:
            interpreter(code, input("Input: "))
        else:
            interpreter(code, "")
    
        print()
        print("End of program.")
        print()
    

if __name__ == "__main__":
    main()