Three tour Python: Python basic data types

A, python operator

Arithmetic operators:

2. Comparison operators

3. assignment operator:

4. Logical Operators:

The Operator members:

Second, the basic data types

int (integer)
　　on a 32-bit machine, an integer number of bits is 32 bits, in the range of -2 31 to 2 31 - 1 ~ -2147483648 2147483647 i.e.
　　on the 64-bit system, the number of bits is 64-bit integer , in the range of -2 63 to 2 63-1 ~ 9223372036854775807 i.e. -9223372036854775808
Boolean value boolean
true or false
　　1 or 0
String 'str'

"hello world"

String common functions:
removing a blank
segmentation
length
index
sections

List (list)

name_list = ['alex', 'seven', 'eric']
或
name_list ＝ list(['alex', 'seven', 'eric'])

Basic operation:

Index
slice
an additional
deletion
length
slice
loop
contains

Ganso (tuple)
创建Ganso:

ages = (11, 22, 33, 44, 55)
或
ages = tuple((11, 22, 33, 44, 55))

Basic operation:
index
slicing
cycle
length
comprising

Dictionary (disorder) (dict) PS: circulation, range, continue and break
create a dictionary:

person = {"name": "mr.wu", 'age': 18}
或
person = dict({"name": "mr.wu", 'age': 18})

Common operations:

Index
added
delete
key, value, key to
cycle
length

Other block
1) for loop: loop order users according to the content object may be iterative,
the PS: BREAK, Continue

a = [11,22,33,44]
for item in a:
    print item

2) enumrate: adding the number of iterations objects

a= [11,22,33]
for k,v in enumerate(a, 1):
    print(k,v)```

3）range和xrange：指定范围，生成指定的数字

(1, 10) Print Range
# Results: [1, 2, 3, 4, 5, 6, 7, 8, 9]

Range Print (1, 10, 2)
# Results: [1, 3, 5, 7, 9]

Range Print (30, 0, -2)
# Results: [30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2]

**课后练习：**

一、元素分类
有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。
即： {'k1': 大于66的所有值, 'k2': 小于66的所有值}

二、查找
查找列表中元素，移除每个元素的空格，并查找以 a或A开头 并且以 c 结尾的所有元素。
    li = ["alec", " aric", "Alex", "Tony", "rain"]
    tu = ("alec", " aric", "Alex", "Tony", "rain") 
    dic = {'k1': "alex", 'k2': ' aric',  "k3": "Alex", "k4": "Tony"}

三、输出商品列表，用户输入序号，显示用户选中的商品
    商品 li = ["手机", "电脑", '鼠标垫', '游艇']

四、购物车
功能要求：
要求用户输入总资产，例如：2000
显示商品列表，让用户根据序号选择商品，加入购物车
购买，如果商品总额大于总资产，提示账户余额不足，否则，购买成功。
附加：可充值、某商品移除购物车

Goods = [
{ "name": "computer", ". price": 1999},
{ "name": "mouse", ". price": 10},
{ "name": "yacht", "price": 20} ,
{ "name": "beauty", ". price": 998},
]

五、用户交互，显示省市县三级联动的选择
dic = {
    "河北": {
        "石家庄": ["鹿泉", "藁城", "元氏"],
        "邯郸": ["永年", "涉县", "磁县"],
    }
    "河南": {
        ...
    }
    "山西": {
        ...
    }
 
}

Three tour Python: Python basic data types

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