Python Lists Advanced

ll = [10, 20, 30, 40, 50]

# insert, remove, pop
ll.remove(20) #[10, 30, 40, 50]
ll.pop() # #[10, 30, 40]

ll = [1, 3, 5, 'seven']
ll.insert(0, 2) 
print(ll) # [2, 1, 3, 5, 'seven']

ll.pop(2) # pops 2nd index element
print(ll) # [2, 1, 5, 'seven']

ll.pop() # takes out last item
print(ll) # [2, 1, 5]

# Slice
gg = [1, 3, 5, 'seven', 'eight', 'nine', [10, 20,]]
print(gg[1:4])  # [3, 5, 'seven']
print(gg[3:])  # ['seven', 'eight', 'nine', [10, 20]]
print(gg[:3])  # [1, 3, 5]
print(gg[:])  # [1, 3, 5, 'seven', 'eight', 'nine', [10, 20]]

print(gg[-1:]) # [[10, 20]]
print(gg[:-1]) # [1, 3, 5, 'seven', 'eight', 'nine']

print(gg[-3:-1]) # ['eight', 'nine']

# list[start:stop:step]
print(gg[0:7:2]) # [1, 5, 'eight', [10, 20]]

ff = [1, 3, 5, 'seven', 'eight', 'nine']
print(ff) #[1, 3, 5, 'seven', 'eight', 'nine']
ff[2:2] = ['test']
print(ff) # [1, 3, 'test', 5, 'seven', 'eight', 'nine']
ff[1:3] = []
print(ff) # [1, 5, 'seven', 'eight', 'nine']

del ff[::2] # Delete even numbred indeces
print(ff)  # [5, 'eight']

# Concatenate
kk = [1, 2, 3, 4] # [1, 2, 3, 4]
kk += 'ab' # since string, it takes as two elements
print(kk) # [1, 2, 3, 4, 'a', 'b']

kk += ['c', 'd']
print(kk) # [1, 2, 3, 4, 'a', 'b', 'c', 'd']

kk.extend(['e', 'f'])
print(kk) # [1, 2, 3, 4, 'a', 'b', 'c', 'd', 'e', 'f']

# List Vs Array
# Array has homogenous elements
# Python arrays are just wrappers for C language
import array
# type: 'd' (float), initializer list: [1, 2, 3]
newArray = array.array('i', [1, 2, 3])
print(newArray) # array('i', [1, 2, 3])