Cork Interpreter

#This runs a Cork file.
#To use it, open your command line in the proper directory and run 'python [thisfile] [corkfileplaintext]'.
#Tell me about your results and good luck!
from sys import stdin, stdout, argv, exit
def lify(instr):
    z,result,ns=0,[],'0123456789'
    while z<len(instr):
        if instr[z] in '><+-.a,i':
            result.append(instr[z])
        if instr[z]=='!':
            tmpr=''
            z+=1
            if not instr[z] in ns:
                exit('Parser found ! and expected a number; instead got {0} at instruction {1}'.format(instr[z],z))
            while instr[z] in ns:
                tmpr+=instr[z]
                z+=1
            result.append(int(tmpr))
            z-=1
        z+=1
    return result

def run(instr):
    code,ptr,cptr,result = lify(instr),128,0,''
    tape = [0]*257
    while ptr<len(tape) and ptr>=0 and cptr<len(code):
        if code[cptr]=='>':
            ptr+=1
        if code[cptr]=='<':
            ptr-=1
        if code[cptr]=='+':
            tape[ptr]+=1
        if code[cptr]=='-':
            tape[ptr]-=1
        if code[cptr]=='.':
            result+=(str(tape[ptr])+' ')
        if code[cptr]=='a':
            result+=chr(tape[ptr])
        if code[cptr]==',':
            stdout.write('#-->')
        tape[ptr]=int(stdin.readline())
        if code[cptr]=='i':
            stdout.write('A-->')
        tape[ptr]=int(stdin.readline())
        if type(code[cptr])==int and tape[ptr]!=0:
            cptr=code[cptr]
    else:
        cptr+=1
    print result
if __name__ == '__main__':
    s = open(argv[1], 'r')
    cfile = s.read()
    cfile = filter(lambda x:x in '><+-ai.,!0123456789',cfile)
    run(cfile)
    s.close()