Question

I have two transform cases:

s = "foo bar" #-> "foo bar &"
s = "foo ! bar" # -> "foo & ! bar" -> notice not '&!'

I did it like this:

t = s.split("!", 1)
t[0] = t[0] + "  &"
" !".join(t)

What’s a more pythonic way to do the same?

Answer 1

str.partition is built for the purpose of operator parsing:

p = s.partition(' !')
print p[0]+' &'+p[1]+p[2]

It is adapted to prefix and infix operator when parsing from left to right. The fact it always returns a 3-tuple allows to use it even when your operator is not found and apply an action on your result as shown above.