I have the following code:
import string
import random
d =[random.choice(string.uppercase) for x in xrange(3355)]
s = "".join(d)
print s
At the moment it prints out a random sequence of letters from the alphabet. But, i need it to print out a sequence of letters containing only four letters for example 'A', 'C', 'U', 'G'. How would this be accomplished?
Thanks
Quinn
Change the set you are asking random.choice to pick from:
import random
d =[random.choice('ACUG') for x in xrange(3355)]
s = "".join(d)
print s
Edit: As SilentGhost points out, if your ultimate goal is only to make a string, skipping the intermediate list is more memory-efficient:
s = "".join(random.choice('ACUG') for x in xrange(3355))
just replace string.uppercase with the sequence (list or string, for example) containing your choices.
Your question is not clear. Do you mean that you want to choose a string only 4 in length? If so then do:
d =[random.choice(string.uppercase) for x in xrange(4)]
Or if you want to choose from a list of only four choices, then do:
d =[random.choice("ACUG") for x in xrange(3355)]
I think the OP is wanting to pre-select a 4-character sample from string.uppercase, then create a 3355 item string based on that:
import string
import random
num_samples = 4
char_sample = random.sample(string.uppercase, num_samples)
d =[random.choice(char_sample) for x in xrange(3355)]
s = "".join(d)
print s
print char_sample
In this case, random.sample(population, sample_count) will take care of that first requirement quite nicely.
However, I agree with the other answers/comments that this question is a bit vague.
