> arr = ["one","two","three"]
> arr[0]
'one'
# 动态扩容
> arr.append(4)
> arr
['one', 'two', 'three', 4]
# 删除一个元素
> del arr[2]
> arr
['one', 'two', 4]

> t = 'one','two',3
> t
('one', 'two', 3)
> t.append(4)
AttributeError: 'tuple' object has no attribute 'append'
> del t[0]
TypeError: 'tuple' object doesn't support item deletion

> t+(1,)
('one', 'two', 3, 1)
> tcopy = t+(1,)
> tcopy
('one', 'two', 3, 1)
> id(tcopy)
4604415336
> id(t)
4605245696

# 使用时指定元素数据类型为`float`
> arr = array.array('f', (1.0, 1.5, 2.0, 2.5))
> arr
array('f', [1.0, 1.5, 2.0, 2.5])
# 修改一个元素
> arr[1]=12.45
> arr
array('f', [1.0, 12.449999809265137, 2.0, 2.5])
# 删除一个元素
> del arr[2]
> arr
array('f', [1.0, 12.449999809265137, 2.5])
# 增加一个元素
> arr.append(4.89)
> arr
array('f', [1.0, 12.449999809265137, 2.5, 4.889999866485596])
# 如果将一个字符串类型数据存储到一个浮点数的数组将会报错
> arr[0]='hello'
TypeError: must be real number, not str

> s ='123abc'
> s
'123abc'
> s[0]
'1'
> s[2]
'3'
# 字符串是不可变的序列，不能删除其中的元素
> del s[1]
TypeError: 'str' object doesn't support item deletion 
# 要对字符串进行操作，可以转化成list 
> sn = list(s)
> sn
['1', '2', '3', 'a', 'b', 'c']
> sn.append(9)
> sn
['1', '2', '3', 'a', 'b', 'c', 9]
# 字符串中的元素也是字符串对象
> type(s[2])
<class 'str'>
> type(s)
<class 'str'>

> s2 = s+'33'
> s2
'123abc33'
> id(s2)
4605193648
> id(s)
4552640416

> b = bytes([0,2,4,8])
> b[2]
4
> b
b'\x00\x02\x04\x08'
> b[0]=33
TypeError: 'bytes' object does not support item assignment
> del b[0]
TypeError: 'bytes' object doesn't support item deletion

> ba = bytearray((1,3,5,7,9))
> ba
bytearray(b'\x01\x03\x05\x07\t')
> ba[1]
3
# 删除一个元素
> del ba[1]
> ba
bytearray(b'\x01\x05\x07\t')
> ba[0]=2
> ba[0]
2
# 添加一个元素
> ba.append(6)
# 只能添加字节
> ba.append(s)
TypeError: 'str' object cannot be interpreted as an integer
> ba
bytearray(b'\x02\x05\x07\t\x06')
# 字节的范围是0-256
> ba[2]=288
ValueError: byte must be in range(0, 256)

# bytearray转成bytes将生成一个新对象
> bn = bytes(ba)
> id(bn)
4604114344
> id(ba)
4552473544

> tuple(l)
('a', 'b', 'c')

> t
('a', 'b', 'c')
> list(t)
['a', 'b', 'c']

> l = list('abc')
> l
['a', 'b', 'c']

> l
['a', 'b', 'c']
> ''.join(l)
'abc'

> s = '123'
> bytes(s)
TypeError: string argument without an encoding
> bytes(s,encoding='utf-8')
b'123'
# 或者使用str的encode()方法
> s.encode()
b'123'

> b = b'124'
> b
b'124'
> type(b)
<class 'bytes'>
> str(b,encoding='utf-8')
'124'
# 或使用bytes的decode()
> b.decode()
'124'