1、列表
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names = ['Alex',"Tenglan",'Eric']
print (names[0])
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names = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
print (names[1:4])
names.append("xiao")
print (names)
names.insert(2,"强行从Eric前面插入")
print (names)
names[2]="该换人了"
print (names)
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del names[2]
print (names)
names.remove("Eric")
print (names)
names.pop()
print (names)
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b = [1,2,3]
names.extend(b)
print (names)
name_copy=names.copy()
print (name_copy)
names=['Alex', 'Tenglan', 'Amy', 'Tom', 'Amy', 1, 2, 3]
print (names.count("Amy"))
names[-3] = '1'
names[-2] = '2'
names[-1] = '3'
names.sort()
print(names)
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names.reverse()
print(names)
print (names.index("Amy"))
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2、元组
元组其实跟列表差不多，也是存一组数，只不是它一旦创建，便不能再修改，所以又叫只读列表
语法
names = ("alex","jack","eric")
它只有2个方法，一个是count,一个是index，完毕。
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names = ("alex","jack","eric")
print (names.count("alex"))
print (names.index("jack"))
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3、字符串操作
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name='test'
print (name[0].capitalize())
name = "TeSt"
print (name.casefold())
print (name.center(50,"-"))
print (name.encode())
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name = "TeStLi"
print(name.endswith("Li"))
print ("Alex\tLi".expandtabs(10))
print (name.find('A'))
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msg = "my name is {}, and age is {}"
print (msg.format("alex",22))
msg = "my name is {1}, and age is {0}"
print (msg.format("alex",22))
msg = "my name is {name}, and age is {age}"
print (msg.format(age=22,name="ale"))
print (msg.format_map({'name': 'alex', 'age': 22}))
print (msg.index('a') )
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print ('9aA'.isalnum())
print ('9'.isdigit())
str = u"this2009"
print (str.isnumeric())
str = u"23443434"
print (str.isnumeric())
print (str.isprintable())
print (str.isspace())
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print (str.isupper())
print ("|".join(['alex','jack','rain']))
intab = "aeiou"
outtab = "12345"
trantab = str.maketrans(intab, outtab)
str = "this is string example....wow!!!"
print (str.translate(trantab))
print (msg.partition('is'))
print ("alex li, chinese name is lijie".replace("li", "LI", 1))
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str = "this is string example....wow!!!"
print (str.swapcase())
print (msg.zfill(40))
print (msg.ljust(40,"-"))
print (msg.rjust(40, "-"))
b="ddefdsdff_哈哈"
print (b.isidentifier())
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4、字典操作
字典的特性：
dict是无序的
key必须是唯一的,so 天生去重
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info = {
'stu1101': "TengLan Wu",
'stu1102': "LongZe Luola",
'stu1103': "XiaoZe Maliya",
}
info["stu1104"] = "Python "
print (info)
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info['stu1101'] ="test"
print (info)
info.pop("stu1101")
print (info)
del info['stu1103']
print (info)
info = {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}
info.popitem()
print (info)
info = {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}
print ("stu1102" in info)
print (info.get("stu1102"))
print (info["stu1102"])
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print (info["stu1105"])
for key in info:
print(key,info[key])
for k,v in info.items():
print(k,v)
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5、集合操作
集合是一个无序的，不重复的数据组合，它的主要作用如下：
去重，把一个列表变成集合，就自动去重了
关系测试，测试两组数据之前的交集、差集、并集等关系
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s = set([3,5,9,10])
t = set("Hello")
a = t | s
b = t & s
c = t – s
d = t ^ s
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基本操作：
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t.add('x')
s.update([10,37,42])
使用remove()可以删除一项：
t.remove('H')
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len(s)
set 的长度
x in s
测试 x 是否是 s 的成员
x not in s
测试 x 是否不是 s 的成员
s.issubset(t)
s <= t
测试是否 s 中的每一个元素都在 t 中
s.issuperset(t)
s >= t
测试是否 t 中的每一个元素都在 s 中
s.union(t)
s | t
返回一个新的 set 包含 s 和 t 中的每一个元素
s.intersection(t)
s & t
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返回一个新的 set 包含 s 和 t 中的公共元素
s.difference(t)
s - t
返回一个新的 set 包含 s 中有但是 t 中没有的元素
s.symmetric_difference(t)
s ^ t
返回一个新的 set 包含 s 和 t 中不重复的元素
s.copy()
返回 set “s”的一个浅复制
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6、文件操作
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f = open('lyrics')
first_line = f.readline()
print('first line:', first_line)
print('我是分隔线'.center(50, '-'))
data = f.read()
print(data)
f.close()
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7、字符编码与转码
需知:
1.在python2默认编码是ASCII, python3里默认是unicode
2.unicode 分为 utf-32(占4个字节),utf-16(占两个字节)，utf-8(占1-4个字节)， so utf-16就是现在最常用的unicode版本， 不过在文件里存的还是utf-8，因为utf8省空间
3.在py3中encode,在转码的同时还会把string 变成bytes类型，decode在解码的同时还会把bytes变回string
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python2
import sys
print(sys.getdefaultencoding())
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msg = "我爱北京天安门"
msg_gb2312 = msg.decode("utf-8").encode("gb2312")
gb2312_to_gbk = msg_gb2312.decode("gbk").encode("gbk")
print(msg)
print(msg_gb2312)
print(gb2312_to_gbk)
python3
import sys
print(sys.getdefaultencoding())
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msg = "我爱北京天安门"
msg_gb2312 = msg.encode("gb2312")
gb2312_to_unicode = msg_gb2312.decode("gb2312")
gb2312_to_utf8 = msg_gb2312.decode("gb2312").encode("utf-8")
print(msg)
print(msg_gb2312)
print(gb2312_to_unicode)
print(gb2312_to_utf8)
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本文转自 corasql 51CTO博客，原文链接：http://blog.51cto.com/corasql/1910454，如需转载请自行联系原作者
