def complement(dna):
dna2= ""
for letter in dna:
if(letter == 'A'):
dna2 += 'T'
elif(letter == 'C'):
dna2 += 'G'
elif(letter == 'T'):
dna2 += 'A'
elif(letter == 'G'):
dna2 += 'C'
return dna2
def reverse_complement(dna):
dna2 = complement(dna)
x = dna2[::-1]
return x
sites = []
def restriction_sites(dna):
dna3 = reverse_complement(dna)
for i in range(4,12,2):
for x in dna3:
if(dna[x:x+1] == dna3[x:x+1]):
sites.append((dna[x+1], dna[x+i], dna[x:x+i]))
dna = 'TCAATGCATGCGGGTCTATATGCAT'
print(dna)
print(complement(dna))
print(reverse_complement(dna))
print(restriction_sites(dna))
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