Question

Suppose I have a function like the following:

bigrams=[(k,v) for (k,v) in dict_bigrams.items()
         if k[:pos_qu]==selection[:pos_qu]
         and (k[pos_qu+1:]==selection[pos_qu+1:] if pos_qu!=1)
         and k[pos_qu] not in alphabet.values()]

I want to make the second condition, namely k[pos_qu+1:]==selection[pos_qu+1:] dependent from another if statement, if pos_qu!=1. I tried (as shown above) by including the two together into parentheses but python flags a syntax error at the parentheses

Answer 1

If I understand your requirement correctly, you only want to check k[pos_qu+1:]==selection[pos_qu+1:] if the condition pos_qu!=1 is also met. You can rephrase that as the following condition:

pos_qu==1 or k[pos_qu+1:]==selection[pos_qu+1:]

Putting this into your comprehension:

bigrams=[(k,v) for (k,v) in dict_bigrams.items()
         if k[:pos_qu]==selection[:pos_qu]
         and (pos_qu==1 or k[pos_qu+1:]==selection[pos_qu+1:])
         and k[pos_qu] not in alphabet.values()]