Second week working in Python, I am struggling to figure out how to ammend block so that translation starts at "atg" . Any help or suggestions would greatly be appreciated. Thank you

Got the translation program running but I need it to only start at "atg" reading through first 3 elements of seq. Code should be generic for any seq

out=[]
for i in range(4,len(dna),3):
 triplet=dna[i:i+3] #groups elements of DNA into triplets
 try: 
  amino=xlate[triplet] #generates string of AA for each triplet using dictionary
  if amino=='0':break
 except:
   break
 out.append(amino) 
out="".join(out)
print(out)