#!python
 
"""
lists (arrays) in python
 
http://www.diveintopython.org/native_data_types/lists.html
"""
 
 
#### define list
 
ls = ['a', 'b', 'c', 'd', 'e']
 
 
 
###### get value from list
 
ls = ['a', 'b', 'c', 'd', 'e']
 
print ls[0]
# a
 
print ls[2]
# c
 
print ls[-1]
# e
 
print ls[-2]
# d
 
 
 
###### slice
 
ls = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
 
print ls[0:2]
# ['a', 'b']
 
print ls[1:2]
# ['b']
 
print ls[:4]
# ['a', 'b', 'c', 'd']
 
print ls[4:]
# ['e', 'f', 'g']
 
 
 
###### list (or string!) reverse
 
ls = ['a', 'b', 'c', 'd', 'e']
print ls[::-1]
# ['e', 'd', 'c', 'b', 'a']
 
s = "My String"
print s[::-1]
# gnirtS yM
 
 
 
###### add element, extend list, merge lists
 
## adding elements
ls = ['a', 'b', 'c', 'd', 'e']
ls.append('f')
print ls 
# ['a', 'b', 'c', 'd', 'e', 'f']
 
ls = ['a', 'b', 'c', 'd', 'e']
ls2 = ['f', 'g']
ls.append(ls2)
print ls 
# ['a', 'b', 'c', 'd', 'e', ['f', 'g']]
 
## inserting elements
ls = ['a', 'b', 'c', 'd', 'e']
ls.insert(2, 'b1')
print ls 
# ['a', 'b', 'b1', 'c', 'd', 'e']
 
## extending list or merging lists
ls = ['a', 'b', 'c', 'd', 'e']
ls.extend(['f', 'g'])
print ls 
# ['a', 'b', 'c', 'd', 'e', 'f', 'g']
 
ls = ['a', 'b', 'c', 'd', 'e']
ls2 = ['f', 'g']
ls.extend(ls2)
print ls 
# ['a', 'b', 'c', 'd', 'e', 'f', 'g']
 
ls = ['a', 'b', 'c', 'd', 'e']
ls2 = ['f', 'g']
ls = ls + ls2
print ls 
# ['a', 'b', 'c', 'd', 'e', 'f', 'g']
 
 
###### remove element from list
 
ls = ['a', 'b', 'c', 'd', 'e']
del ls[0]
print ls 
# ['b', 'c', 'd', 'e', 'f', 'g']
print ls[0]
# b