python dvorak/qwerty converter

#!/usr/bin/env python3
import sys

def main(charsets):
    source_layout = sys.argv[1]
    passwd = sys.argv[2]

    if not source_layout in charsets:
        print("Charset {} not found".format(source_layout))
        print("Available charsets:", *charsets.keys())
    if checkpass(passwd, charsets) == 0:
        for charset in charsets:
            if charset == source_layout: continue
            charsetpass = ''
            for char in passwd:
                charsetpass = charsetpass + charsets[source_layout][charsets[charset].index(char)]
            print("keyboard: {}\tsystem: {}\ttext: {}".format(source_layout, charset, charsetpass))


dvorak =            ''' `1234567890[]',.pyfgcrl/=aoeuidhtns-\<;qjkxbmwvz~!@#$%^&*(){}"<>PYFGCRL?+AOEUIDHTNS_|>:QJKXBMWVZ''' # linux dvorak..
dvorak_windows =    ''' `1234567890[]',.pyfgcrl/=aoeuidhtns-\\\\;qjkxbmwvz~!@#$%^&*(){}"<>PYFGCRL?+AOEUIDHTNS_||:QJKXBMWVZ''' # windows dvorak..
qwertz =            ''' ^1234567890ß´qwertzuiopü+asdfghjklöä#<yxcvbnm,.-°!"§$%&/()=?`QWERTZUIOPÜ*ASDFGHJKLÖÄ'>YXCVBNM;:_'''
qwerty =            ''' `1234567890-=qwertyuiop[]asdfghjkl;'\\\\zxcvbnm,./~!@#$%^&*()_+QWERTYUIOP{}ASDFGHJKL:"||ZXCVBNM<>?'''

charsets = {
    'dvorak':dvorak,
    'qwerty':qwerty,
    'qwertz':qwertz,
    'dvorak_windows':dvorak_windows
}



def checkpass(passwd, charsets):
    clear = True
    for c in passwd:
        for charset in charsets:
            if c not in charsets[charset]:
                print("Character {} not properly convertable to charset {}".format(c, charset))
                clear = False
    if not clear:
        return -1
    return 0

def usage():
    print("Usage: {} typing_layout text".format(sys.argv[0]))

if __name__ == '__main__':
    if not len(sys.argv) == 3:
        usage()
    else:
        main(charsets)