Python3.7從無到有學習筆記

#Python3.7

1. 變量

>>> x=1
>>> y=2
>>> print(x+y)
3

2. 註釋

#單行註釋
'''多行註釋'''

3. 布爾類型

>>> x=1
>>> y=2
>>> x<y
True
>>> x>y
False
#判斷數值或者命令執行結果

3. 定義列表

>>> names = ["zhangsan","lisi","wangwu","zhaoliu","liubei"]
>>> names
["zhangsan","lisi","wangwu","zhaoliu","liubei"]

• 此處應用了列表中的隱藏語法：下標

names = ["zhangsan","lisi","wangwu","zhaoliu","liubei"]
names = ["0"			 ,"1"		,"2"		 ,"3"			 ,"4"			]
names = ["-5"			 ,"-4"	,"-3"		 ,"-2"		 ,"-1"			]

• 正數和倒數的區別

>>> names
['zhangsan', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names[-4]
'wangwu'
>>> names[4]
'liubei'

• 插入

>>> names = ["zhangsan","lisi","wangwu","zhaoliu","liubei"]
>>> names[1]
'lisi'
>>> names.insert(1,"myc")
>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei']

• 追加

>>> names.append("guanyu")
>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 刪除

>>> names = ['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names[1]
'myc'
>>> names[-6]
'myc'
>>> del names[-6]
#del names[1] 這麼寫也可以
>>> names
['zhangsan', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 改

>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names [1] = "mayancheng"
>>> names
['zhangsan', 'mayancheng', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 查，存在返回True，不存在返回False。和shell的0和1類似

>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> "myc" in names
True
>>> "myc2" in names
False

• 查找並刪除

>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names.index("myc")
1
>>> del names[names.index("myc")]
>>> names
['zhangsan', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 查找並修改

>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names.index("myc")
1
>>> names[names.index("myc")] = "mayancheng"
>>> names
['zhangsan', 'mayancheng', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 在指定位置前追加

>>> names
['zhangsan', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']
>>> names.insert(names.index("myc"),"mycgogogo")
>>> names
['zhangsan', 'mycgogogo', 'myc', 'lisi', 'wangwu', 'zhaoliu', 'liubei', 'guanyu']

• 讀取用戶指令

>>> names = input("請輸入您的用戶名：")
請輸入您的用戶名：vip
>>> names
'vip'
>>> print(names)
vip

• 格式化打印

%s	#字符串
input #接收到的所有數據都以字符串處理
%d	#整數
int		#接收到的數據以整數來處理
%f	#浮點數（小數）
float	#接收到的數據以浮點數來處理

name = input("姓名：")
age = int(input("年齡："))
height = float(input("身高："))
question = input("是否確認以上信息正確？")

msg = '''
=========Personal Info========
Name        : %s
Agg         : %d
Height      : %f
question    : %s
==============End=============
''' % (name,age,height,question)

print(msg)

if question == "y" or question == "Y":
    print("已記錄")
else:
    print("請重新輸入")