codon_table = {
     "UUU": "F", "UUC": "F", "UUA": "L", "UUG": "L", "UCU": "S",
     "UCC": "S", "UCA": "S", "UCG": "S", "UAU": "Y", "UAC": "Y",
     "UAA": "_", "UAG": "_", "UGA": "_", "UGU": "C", "UGC": "C",
     "UGG": "W", "CUU": "L", "CUC": "L", "CUA": "L", "CUG": "L",
     "CCU": "P", "CCC": "P", "CCA": "P", "CCG": "P", "CAU": "H",
     "CAC": "H", "CAA": "Q", "CAG": "Q", "CGU": "R", "CGC": "R",
     "CGA": "R", "CGG": "R", "AUU": "I", "AUC": "I", "AUA": "I",
     "AUG": "M", "ACU": "T", "ACC": "T", "ACA": "T", "ACG": "T",
     "AAU": "N", "AAC": "N", "AAA": "K", "AAG": "K", "AGU": "S",
     "AGC": "S", "AGA": "R", "AGG": "R", "GUU": "V", "GUC": "V",
     "GUA": "V", "GUG": "V", "GCU": "A", "GCC": "A", "GCA": "A",
     "GCG": "A", "GAU": "D", "GAC": "D", "GAA": "E", "GAG": "E",
     "GGU": "G", "GGC": "G", "GGA": "G", "GGG": "G"}

>seq1
ATGCTGATGATAGGTATGGGTA
GATAGATGAGAGAGATGAGAAT
>seq2
ATGCGATGATAGATG
>seq3
ATGC

def dna_to_protein(inputFilename, outputFilename="protein.fasta"):
        inputFile = open(inputFilename, "r")
        outputFile = open(outputFilename, "w")
        for line in inputFile:
            line = line.strip()
            if line and not line.startswith('>'):
                line = line.replace("T","U")
                for i in range(0,len(line),3):
                    codon=line[i:i+3]
                    if len(codon) == 3:
                        amino=codon_table[codon]
                        if amino != "_":
                            line = line + amino
                    elif amino == "_":
                        line = line + amino
                        return line
                        print(line, file=outputFile)


dna_to_protein("dna.fasta", "protein.fasta")

>seq1
MLMIGMGR_MREMRX
>seq2
MR__M
>seq3
MX