Slices

The slicing operator s[i:j]

  • Extracts all elements s[n] where i <= n < j
     a = [0,1,2,3,4,5,6,7,8]
     b = a[3:6]      # b = [3,4,5]
  • If either index is omitted, beginning or end of sequence is assumed
     c = a[:3]       # c = [0,1,2]
     d = a[5:]       # d = [5,6,7,8]
  • Negative index is taken from the end of the sequence
     e = a[2:-2]     # e = [2,3,4,5,6]
     f = a[-4:]      # f = [5,6,7,8]
  • No indices just makes a copy (which is sometimes useful)
     g = a[:]        # g = [0,1,2,3,4,5,6,7,8]
<<< O'Reilly OSCON 2000, Introduction to Python, Slide 56
July 17, 2000, beazley@cs.uchicago.edu
>>>