1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
print("print practice-------------")
print("hello world")
print("I\'m ok")
print("-------------")
print(True and True)
print(True or False)
print(not False)
print("-------------")
print(ord('A'))
print("-------------")
print('\u4e2d\u6587')
print("ABC".encode("ascii"))
print("ABC".encode("utf-8"))
print("中文".encode('gb2312'))
print("-------------")
print("1.23e9: ",1.23e9)
print("name:%s,age:%d" % ("yifei",20))
print("list practice-------------")
print("list，列表，是一种有序的数据集合，可以随时添加删除其中的元素")
print("需要用[]包裹")
classmates = ["aaa","bbb","ccc"]
print("classmates:",classmates)
print("len:",len(classmates))
print("取倒数第n个,",classmates[-1],classmates[-2],classmates[-3])
classmates.append("ddd")
print("append element:",classmates)
classmates.insert(1,"jack")
print("insert element:",classmates)
classmates.pop()
print("delete last element:",classmates)
classmates.pop(3)
print("delete n\'th ele:",classmates)
classmates.append(["eee","fff"])
print("append a list:",classmates)
print("tuple practice-------------")
print("tuple,元组，也是有序列表，跟list非常像，但是一旦初始化就不能修改")
print("用()包裹")
t1=(1,2)
t2=()
print("t:",t1," t2:",t2)
t3=(3,)
print("定义只有一个元素的tuple，需要(3,) :",t3)
print("如果tuple里面包含list，那么其中的list是可以变的")
t=('a','b',['A','B'])
print("t:",t)
t[2][0]='X'
t[2][1]='Y'
print("t:",t)
print("if-------------")
age=20
if age>=18:
print("adult")
elif age>=6:
print("tennager")
else:
print("kid")
print("input-------------")
birth="2009"
if birth > "2000":
print("00后")
else:
print("00前")
birth2=int(birth)
print(birth2)
print("cal list sum-------------")
sum=0
for x in [1,2,3,4,5,6,7,8,9,10]:
sum=sum+x
print(sum)
print("list(range(5)):",list(range(5)))
sum=0
for x in range(101):
sum=sum+x
print("0-100 sum:",sum)
print("while-------------")
sum=0
n=99
while n>0:
sum=sum+n
n=n-2
print(sum)
print("依次打印list-------------")
l=["tom","lisa","adam"]
for x in l:
print("hello",x)
print("continue and break-------------")
sum2=0
nn=0
while True:
if nn==5:
nn=nn+1
continue
if nn>=10:
break
nn=nn+1
sum2=sum2+nn
print(sum2)
print("dict-------------")
print("dict，字典，类似c++中的map，用{}包裹")
d={"daming":95,"bob":99}
print(d)
print("d[\"daming\"]:",d["daming"])
d["sam"]=100
print(d)
print("判断jack是否在dict中 \"jack\" in d:","jack" in d)
d.get("daming")
d.get("ddd")
print(d.get("aaa",-1))
d.pop("daming")
print(d)
print("set-------------")
s=set([1,1,2,2,3])
print(s)
s.add(4)
print(s)
s.remove(1)
print(s)
s2=set([3,4,5])
print(s & s2)
print(s | s2)
print("不可变对象-------------")
print("对不可变对象a调用replace，a不变")
a="abc"
b=a.replace('a','A')
print("a: ",a)
print("a:",a," b:",b)
|