Dna / Rna python processing

RNA3 = {
 "AAA": "Lys",
 "AAC": "Asn",
 "AAG": "Lys",
 "AAU": "Asn",
 "ACA": "Thr",
 "ACC": "Thr",
 "ACG": "Thr",
 "ACU": "Thr",
 "AGA": "Arg",
 "AGC": "Ser",
 "AGG": "Arg",
 "AGU": "Ser",
 "AUA": "Lle",
 "AUC": "Lle",
 "AUG": "Mel",
 "AUU": "Lle",
 "CAA": "Gln",
 "CAC": "His",
 "CAG": "Gln",
 "CAU": "His",
 "CCA": "Pro",
 "CCC": "Pro",
 "CCG": "Pro",
 "CCU": "Pro",
 "CGA": "Arg",
 "CGC": "Arg",
 "CGG": "Arg",
 "CGU": "Arg",
 "CUA": "Leu",
 "CUC": "Leu",
 "CUG": "Leu",
 "CUU": "Leu",
 "GAA": "Glu",
 "GAC": "Asp",
 "GAG": "Glu",
 "GAU": "Asp",
 "GCA": "Ala",
 "GCC": "Ala",
 "GCG": "Ala",
 "GCU": "Ala",
 "GGA": "Gly",
 "GGC": "Gly",
 "GGG": "Gly",
 "GGU": "Gly",
 "GUA": "Val",
 "GUC": "Val",
 "GUG": "Val",
 "GUU": "Val",
 "UAA": "Stop",
 "UAC": "Tyr",
 "UAG": "Stop",
 "UAU": "Tyr",
 "UCA": "Ser",
 "UCC": "Ser",
 "UCG": "Ser",
 "UCU": "Ser",
 "UGA": "Stop",
 "UGC": "Cys",
 "UGG": "Trp",
 "UGU": "Cys",
 "UUA": "Leu",
 "UUC": "Phe",
 "UUG": "Leu",
 "UUU": "Phe",
}
AMINOACID_CHEM = {
    "Ala": "CH3-CH(NH2)-COOH",
    "Arg": "HN=C(NH2)-NH-(CH2)3-CH(NH2)-COOH",
    "Asn": "H2N-CO-CH2-CH(NH2)-COOH",
    "Asp": "HOOC-CH2-CH(NH2)-COOH",
    "Cys": "HS-CH2-CH(NH2)-COOH",
    "Gln": "H2N-CO-(CH2)2-CH(NH2)-COOH",
    "Glu": "HOOC-(CH2)2-CH(NH2)-COOH",
    "Gly": "NH2-CH2-COOH",
    "His": "NH-CH=N-CH=C-CH2-CH(NH2)-COOH",
    "Lle": "CH3-CH2-CH(CH3)-CH(NH2)-COOH",
    "Leu": "(CH3)2-CH-CH2-CH(NH2)-COOH",
    "Lys": "H2N-(CH2)4-CH(NH2)-COOH",
    "Met": "CH3-S-(CH2)2-CH(NH2)-COOH",
    "Phe": "Ph-CH2-CH(NH2)-COOH",
    "Pro": "NH-(CH2)3-CH-COOH",
    "Ser": "HO-CH2-CH(NH2)-COOH",
    "Thr": "CH3-CH(OH)-CH(NH2)-COOH",
    "Trp": "Ph-NH-CH=C-CH2-CH(NH2)-COOH",
    "Tyr": "HO-Ph-CH2-CH(NH2)-COOH",
    "Val": "(CH3)2-CH-CH(NH2)-COOH"
}
RNA_CONVERSION = {
    "A": "A",
    "C": "C",
    "G": "G",
    "T": "U"
}

def DNAtoRNA(DNA):
    RNA = ""
    for c in DNA:
        RNA += RNA_CONVERSION[c]
    return RNA

def RNAtoAminoAcid(RNA):
    amino = ""
    i = 0;
    while (i <= len(RNA)-1):
        next3 = RNA[i:3+i];
        if (len(next3) != 3):
            break;
        if (RNA3[next3] == "Stop"):
            break;
        amino += RNA3[next3];
        i+=3;
    return amino;

def AminoAcidtoChem(AMINO):
    chem = ""
    i = 0;
    while (i <= len(AMINO)-1):
        next3 = AMINO[i:3+i];
        if (len(next3) != 3):
            break;
        if (AMINOACID_CHEM[next3] == "Stop"):
            break;
        chem += AMINOACID_CHEM[next3] + " + ";
        i+=3;
    return chem[:-3];