Python 3: List Example

Python3ListExample.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

"""
Introducing Lists easy example

@author: Hank Wang <[email protected]>
@version: 20101010
"""
# Creating Lists
l0 = l1 = ['PS3', 'XBOX', 'Wii']
l2 = list(['pork', 'hotpot', 'beef'])
l3 = list() # empty list
l4 = [1, 3, 5, 7]
l5 = l0[:]  # createing a copy


# Show Lists
print('\n=== Show Lists === ')
print(l0)           # ['PS3', 'XBOX', 'Wii']
print(l1)           # ['PS3', 'XBOX', 'Wii']
print(l2)           # ['pork', 'hotpot', 'beef']
print(l3)           # []
print(l4)           # [1, 3, 5, 7]

# Accessing Lists
# - L[index]
# - L[start:stop:step]
print('\n=== Accessing Lists === ')
print(l1[0])        # PS3
print(l1[-2])       # XBOX
print(l1[1:-1])     # ['XBOX']
print(l1[:2])       # ['PS3', 'XBOX']
print(l1[1:])       # ['XBOX', 'Wii']
print(l1[1:3])      # ['XBOX', 'Wii']
print(l1[:3:2])     # ['PS3', 'Wii']


# Looping Over Lists
print('\n=== Looping Over Lists === ')
for item in l1:
    print(item)

for index, item in enumerate(l2):
    print(index, item)

[print(item) for item in l2]
print("|".join(map(str, l2)))

for index in range(len(l2)):
    print(index)

# Iterator
print('\n=== Iterator === ')
i = iter(l1)            
print(i.__next__())     # PS3
print(i.__next__())     # XBOX

for item in l2.__iter__():
    print(item)


# join string
print('\n=== Join string === ')
print(''.join(l1))      # PS3XBOXWii


# sum
print('\n=== Sum === ')
print(sum(l4))          # 16
print(sum(l4, 4))       # 20
print(float(sum(l4) / len(l4))) # average: 4.0

# Modify element
# - L.append(item)
# - L.extend(sequence)
# - L.insert(index, item)
print('\n=== Modify elements === ')
l1.insert(2, 'Sega')
print(l1)           # ['PS3', 'XBOX', 'Sega', 'Wii']

# 注意 append & extend 的不同
arr = ['a','b','c']
l1.append(arr)
l1.extend(arr)
print(l1)           # ['PS3', 'XBOX', 'SEGA', 'Wii', ['a', 'b', 'c'], 'a', 'b', 'c']

l4[3] = 6
print(l4)           # [1, 3, 5, 6]
 

# Search element
print('\n=== Search element === ')

try:
    print(l1.index('Wii')) # 3
    print(l1.index('pork'))# can't find
except ValueError:
    print('can\'t find')
    
print('Wii' in l1)     # True
print('pork' in l2)    # False


# Count, min, max
print('\n=== Count, min, max === ')
print(l1.count('PS3')) # 1

print(min(l4))      # 1
print(max(l4))      # 6


# Sort
print('\n=== Sort === ')
l5 = [3, 77, 9, 32, 1, 16]

l6 = sorted(l5) # get a sorted copy
print(l5)       # [3, 77, 9, 32, 1, 16]
print(l6)       # [1, 3, 9, 16, 32, 77]

l5.sort()
print(l5)       # [1, 3, 9, 16, 32, 77]


# Reverse
print('\n=== Reverse === ')
print(l4)           # [1, 3, 5, 6]
l4.reverse()

print(l4)           # [6, 5, 3, 1]
l4.reverse()

# Delete element
print('\n=== Delete elements === ')
l1.remove('Wii')
l1.remove(arr)      
print(l1)              # ['PS3', 'XBOX', 'SEGA', 'a', 'b', 'c']

del l4[3]
print(l4)              # [1, 3, 5]

del l4[1:3]
print(l4)              # [1]

# pop
print('\n=== pop === ')
print(l1.pop())        # c
print(l1.pop(-2))      # a
print(l1.pop(3))       # b

# Operator element
print('\n=== Operator === ')
print(l1+l2)        # ['PS3', 'XBOX', 'SEGA', 'pork', 'hotpot', 'beef']
print(l2*2)         # ['pork', 'hotpot', 'beef', 'pork', 'hotpot', 'beef']
print(l3)           # []
l3 += 'NBA'
print(l3)           # ['N', 'B', 'A']