I have a list of strings like the following in Python:
SS = ['T', 'Q', 'T', 'D', 'Q', 'D', 'D', 'Q', 'T', 'D']
Is there anyway I could check how many Ts are directly followed by D, so in this case, there are 2 Ts (second and the last T) that meet the requirement.
I tried this but it was not working though, any advice? thx!
if ['T','Q'] in SS:
print ("yes")
You could do this iteratively checking if the next character was a D and implementing some sort of counter. This is (probably) the tersest, although maybe not the best way.
SS = ['T', 'Q', 'T', 'D', 'Q', 'D', 'D', 'Q', 'T', 'D']
print("".join(SS).count("TD"))
Result:
2
SS = ['T', 'Q', 'T', 'D', 'Q', 'D', 'D', 'Q', 'T', 'D']
print zip(SS, SS[1:]).count(('T', 'D'))
A sequence of single-character strings can be expressed either as your given list or as a multi-character string, the main differences being list methods vs str methods (there's also the tuple type), and mutability.
>>> SS = ['T', 'Q', 'T', 'D', 'Q', 'D', 'D', 'Q', 'T', 'D']
>>> SS_joined = ''.join(SS)
>>> 'TQ' in SS_joined
True
You can always you re.
>>> import re
>>> SS = ['T', 'Q', 'T', 'D', 'Q', 'D', 'D', 'Q', 'T', 'D']
>>> new = ''.join(SS)
>>> len(re.findall('TD',new))
2
