Python listの使い方

lists_basics.py

"""
list: A sequence of items (elements)
    - A list is mutable
    - A list is not array in Python.
    - A list can contain a variety of types.
"""

# 1. create a list

fruit = []
print(fruit)
# >>> []

fruit = ["Apple", "Orange", "Pear"]
print(fruit)
# >>> ['Apple', 'Orange', 'Pear']

squares = [1, 4, 9, 16, 25, 36, 49]
print(squares)
# >>> [1, 4, 9, 16, 25, 36, 49]

chaos = [1, 2.5, "Cat", [1, 3], (5, "apple")]
# >>> [1, 2.5, 'Cat', [1, 3], (5, 'apple')]

# 2. list operations

animals = ["Eagle", "Snake", "Panda", "Lion", "Tiger", "Bear"]

# add

# 注意!!!! listに追加しても、新しいlistは返ってこない。これに気づかないで10分考えた。ここらへんにmutableらしさを感じる。
print(animals.append("Cat"))  # add "Cat" item to the list
# >>> None
print(animals)
# >>> ['Eagle', 'Snake', 'Panda', 'Lion', 'Tiger', 'Bear', 'Cat']

animals.insert(0, "Monkey")  # insert "Monkey" at 0 index
print(animals)
# >>> ['Monkey', 'Monkey', 'Eagle', 'Snake', 'Panda', 'Lion', 'Tiger', 'Bear', 'Cat']

# 注意!!!! insertも同じ。
print(animals.insert(0, "Dog"))
# >>> None

# delete

# count

# retrieve element or index

# sum

# sort

# search