encryption python

program.py --

import random as r

def keygen():
    string="QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm,.<>/;?:'#@~!£$€&*()1234567890 -+_=^"
    str_len=len(string)
    nst=[]
    for i in range(str_len):
        num=r.randint(0,1000)
        nst.append([string[i],num])
    nst.sort(key=lambda x:x[1])
    string=""
    for i in range(str_len):
        string+=nst[i][0]
    return string

def get_file(string,m="r",d=0):
    try:
        file=open(string+".txt",m)
    except:
        print("Whoops... Looks like something bad happened or the file exists. Would recommend encrypting new input text, and then decrypting it.")
    if m=="r":
        d=file.read()
        return d
    elif m=="w":
        file.write(d)
    file.close()

def crypt(d=0,k=0,m=0,p=0):
    nd=""
    if m==0:
        nf=""
    elif m==1:
        p=p.split(",")
    for i in range(len(d)):
        n=k.index(d[i])
        if m==0:
            f=r.randint(1,len(k)-1)
            nd+=k[int(n-f)]
            nf+=str(f)
            if i<len(d)-1:
                nf+=","
        elif m==1: nd+=k[int(p[i])+n-len(k)]
    if m==0: return nd,nf
    elif m==1: return nd


def main_prog():
    choice=input("1. Encrypt text - 'en'\n2. Decrypt text - 'de'\nAnswer: ")
    if choice=="en": encrypt()
    elif choice=="de": decrypt()

def encrypt():
    newkey=keygen()
    input_t=input("Input: ")
    newdata,newnums=crypt(input_t,newkey)
    get_file("key","w",newkey)
    get_file("padlock","w",newnums)
    get_file("text","w",newdata)
    print("Success...")
    main_prog()

def decrypt():
    key=get_file("key")
    padlock=get_file("padlock")
    encrypted=get_file("text")
    decrypted=crypt(encrypted,key,1,padlock)
    print("Text below: ")
    print(decrypted)
    main_prog()

main_prog()

key.txt --

)pts<,D=@?H1vX>Yg:U(qxKWo3$8~4C.wa+n£*T!BbM€5kF7Li^hNd /9AyurVRj#PGf2&Sz0_OeI6-'lQmZ;cEJ

padlock.txt --

34,13,36,34,64

text.txt --

:R5FL