gistfile1.py

def get_length(dna):
    return len(dna)

def is_longer(dna1, dna2):
    return len(dna1) > len(dna2)

def count_nucleotides(dna, nucleotide):
    return dna.count(nucleotide)

def contains_sequence(dna1, dna2):
    return dna1.find(dna2) >= 0

def is_valid_sequence(dna):
    for c in seq:
        if not c in ['A', 'C', 'G', 'T']: return False
    return True

def insert_sequence(dna1, dna2, index):
    return dna1[:index] + dna2 + dna1[index:]

def get_complement(c):
    if c == 'A': return 'T'
    elif c == 'T': return 'A'
    elif c == 'C': return 'G'
    elif c == 'G': return 'C'

def get_complementary_sequence(dna1):
    dna2 = ''
    for c in dna1:
        dna2 += get_complement(c)
    return dna2