>>> T = (1,2,3,4)
>>> len(T)
4
>>> T + (5,6)
(1, 2, 3, 4, 5, 6)
>>> T[0]
1
>>> T.index(4)
3
>>> T.count(4)
1
>>> T[0] = 2   #元组是不可变的
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: ‘tuple‘ object does not support item assignment
>>> T = (‘spam‘,3.0,[11,22,33])
>>> T[1]
3.0
>>> T[2][1]
22
>>> T.append(4) #不可增长或缩短
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: ‘tuple‘ object has no attribute ‘append‘

>>> (1,2) + (3,4)  #生成新的元组
(1, 2, 3, 4)
>>> (1,2) * 4  #生成新的元组
(1, 2, 1, 2, 1, 2, 1, 2)
>>> T = (1,2,3,4)
>>> T[0],T[1:3] #生成新的元组
(1, (2, 3))

>>> f = open(‘data.txt‘,‘w‘)   #当前文件夹下创建新文件
>>> f.write(‘Hello\n‘)  #把hello字符串写入文件
6
>>> f.write(‘world\n‘)
6
>>> f.close()   #关闭文件

>>> f.open(‘data.txt‘,‘r‘)
>>> text = f.read()
>>> text
‘Hello\nworld\n‘
>>> print(text)
Hello
world

>>> text.split()  #文件内容为字符串
[‘Hello‘, ‘world‘]

>>> myfile = open(‘myfile.txt‘,‘w‘)
>>> myfile.write(‘hello textfile\n‘)
15
>>> myfile.write(‘goodbye text file\n‘)
18
>>> myfile.close()
>>> myfile = open(‘myfile.txt‘)
>>> myfile.readline()
‘hello textfile\n‘
>>> myfile.readline()
‘goodbye text file\n‘
>>> myfile.readline()
‘‘

>>> open(‘myfile.txt‘).read()  #一次性全部读取整个文件
‘hello textfile\ngoodbye text file\n‘
>>> print(open(‘myfile.txt‘).read()) #友好的显示
hello textfile
goodbye text file
#如果想要一行一行地扫描一个文本文件，文件迭代器往往是最佳的选择
>>> for line in open(‘myfile.txt‘):
...     print(line,end=‘‘)
...
hello textfile
goodbye text file

>>> data = http://www.mamicode.com/open(‘data.bin‘,‘wb‘)
>>> data.write(b‘\x00\x00\x00\x07spam\x00\x08‘)
10
>>> data.close()
>>> data = http://www.mamicode.com/open(‘data.bin‘,‘rb‘).read()
>>> data
b‘\x00\x00\x00\x07spam\x00\x08‘
>>> data[4:8]
b‘spam‘
>>> data[4]
115
>>> bin(data[4])
‘0b1110011‘

>>> x,y,z = 43,44,45
>>> s = ‘spam‘ #字符串可以直接存至文件
>>> D = {‘a‘:1,‘b‘:2}
>>> L = [1,2,3]
>>> F = open(‘datafile.txt‘,‘w‘)
>>> F.write(s + ‘\n‘) #添加换行符
5
>>> F.write(‘{0},{1},{2}\n‘.format(x,y,z)) #需要转换为字符串
9
>>> F.write(str(L) + ‘$‘ + str(D) + ‘\n‘) #需要转换为字符串
27
>>> F.close()

>>> chars = open(‘datafile.txt‘).read()
>>> chars
"spam\n43,44,45\n[1, 2, 3]${‘b‘: 2, ‘a‘: 1}\n"
>>> print(chars)
spam
43,44,45
[1, 2, 3]${‘b‘: 2, ‘a‘: 1}

>>> F = open(‘datafile.txt‘)
>>> line = F.readline()
>>> line
‘spam\n‘
>>> line.rstrip() #用rstrip方法去掉多余的终止符
‘spam‘
>>> line
‘spam\n‘
>>> line[:-1]#或用分片去掉多余的终止符
‘spam‘
>>> line = F.readline()
>>> line
‘43,44,45\n‘
>>> parts = line.split(‘,‘) #用split方法从逗号中转换为列表
>>> parts
[‘43‘, ‘44‘, ‘45\n‘]
>>> int(parts[1])
44
>>> parts = [int(p) for p in parts] #需要得到真正的整数类型，需要int函数转换
>>> parts
[43, 44, 45]
#还有一个方法可以用内置函数eval进行转换。eval函数能够把字符串当做可执行程序代码（从技术上讲，就是一个含有python表达式的字符串）。
>>> line = F.readline()
>>> line
"[1, 2, 3]${‘b‘: 2, ‘a‘: 1}\n"
>>> parts = line.split(‘$‘) #split从$中转换为列表
>>> parts
[‘[1, 2, 3]‘, "{‘b‘: 2, ‘a‘: 1}\n"]
>>> eval(parts[0]) #eval函数可以把字符串转换为可执行代码
[1, 2, 3]
>>> objects = [eval(p) for p in parts]
>>> objects
[[1, 2, 3], {‘b‘: 2, ‘a‘: 1}]

>>> D = {‘a‘:1,‘b‘:2}
>>> F = open(‘datafile.pkl‘,‘wb‘)
>>> import pickle
>>> pickle.dump(D,F)
>>> F.close()
>>> F = open(‘datafile.pkl‘,‘rb‘)
>>> E = pickle.load(F)
>>> E
{‘b‘: 2, ‘a‘: 1}

##struct打包
>>> F = open(‘data.bin‘,‘wb‘)
>>> import struct
>>> data = http://www.mamicode.com/struct.pack(‘>i4sh‘,7,b‘spam‘,8) #注意字符串必须是二进制b模式
>>> data
b‘\x00\x00\x00\x07spam\x00\x08‘
>>> F.write(data)
10
>>> F.close()

##struct解包
>>> F = open(‘data.bin‘,‘rb‘)
>>> data =http://www.mamicode.com/ F.read()
>>> data
b‘\x00\x00\x00\x07spam\x00\x08‘
>>> values = struct.unpack(‘>i4sh‘,data)
>>> values
(7, b‘spam‘, 8)

>>> dir(struct)
[‘Struct‘, ‘__all__‘, ‘__builtins__‘, ‘__cached__‘, ‘__doc__‘, ‘__file__‘, ‘__lo
ader__‘, ‘__name__‘, ‘__package__‘, ‘__spec__‘, ‘_clearcache‘, ‘calcsize‘, ‘erro
r‘, ‘iter_unpack‘, ‘pack‘, ‘pack_into‘, ‘unpack‘, ‘unpack_from‘]

>>> if type(L) == type([]): print(‘yes‘)
...
yes
>>> if type(L) == list: print(‘yes‘)
...
yes
>>> if isinstance(L,list): print(‘yes‘)
...
yes