Invalid syntax using dict comprehension

问题

Given a list of floats named 'x', I would like to create a dict mapping each x in x[1:-1] to it's neighbors using a dict comprehension. I have tried the following line :

neighbours = {x1:(x0,x2) for (x0,x1,x2) in zip(x[:-2],x[1:-1],x[2:])}

However, the syntax seems to be invalid. What am I doing wrong?

回答1:

Dict comprehensions are only available in Python 2.7 upwards. For earlier versions, you need the dict() constructor with a generator:

dict((x1, (x0,x2)) for (x0,x1,x2) in zip(x[:-2],x[1:-1],x[2:]))

来源：https://stackoverflow.com/questions/10933601/invalid-syntax-using-dict-comprehension