How do I reverse a part (slice) of a list in Python?

Question

Why doesn\'t this work?

# to reverse a part of the string in place 
a = [1,2,3,4,5]
a[2:4] = reversed(a[2:4])  # This works!
a[2:4] = [0,0]             # Thi         


        

Answer 1

Here's a weird example and weirder solution using slicing and a bit of list fundamentals.

Problem: Reverse a list in parts of two.

I/P : [1,2,3,4,5,6]

O/P: [3,2,1,6,5,4]

Soln:

[item for i in range(0,len(l),len(l)/2) for item in l[i:i+len(l)/2][::-1]]

Problem: Reverse the letters of someones name.

E.g Harry Porter

O/p: yrraH retroP

Soln:

' '.join(map(lambda x:x[::-1], s.split()))