Python基礎

一、賦值運行

（1）多賦值

a = b = c = 0

a

0

b

0

c

0

(2)元組賦值

a,b,c = 1,2,3

a

1

b

2

c

3

(3)同步賦值

a,b=1,2

a,b = a+b,a

a

3

b

1

(4)自操作簡化

a+=1

a

4

二、列表索引與切片

（1）列表索引

list_test = [1,2,3,4,5]

list_test[-2]

4

(2)列表切片

list_test[1:3]

[2, 3]

list_test[0:5:2]

[1, 3, 5]

list_test[-2:]

[4, 5]

(2) 秀操作

list_test[::-1]

[5, 4, 3, 2, 1]

# 替換列表某段子列表
list_test[0:2]=[9,8]

list_test

[9, 8, 3, 4, 5]

list_test[:0]=[10,9,8]

list_test

[10, 9, 8, 9, 8, 3, 4, 5]

三、字符串處理

（1）split拆分字符串

str_test = "I am SunYongDi who are you ?"

str_test01 = "SunYongDi"

r_list = str_test.split()

r_list

['I', 'am', 'SunYongDi', 'who', 'are', 'you', '?']

r_list01 = str_test01.split("n")

r_list01

['Su', 'Yo', 'gDi']

(2)strip刪除字符串前後多餘字符

str_test02 = "   孫永荻 啊！ \t \n"

strip_test = str_test02.strip(" 哈哈")

strip_test

'孫永荻 啊！ \t \n'

(3)join 連接列表字符串

list_test = ['2019','10','30']

r_join = "-".join(list_test)

r_join

'2019-10-30'

四、基本操作

# 大小寫轉換
str_00 = "SunYongDi"

str_00.upper()

'SUNYONGDI'

str_00.lower()

'sunyongdi'

# 字符與ASCLL碼的轉換
chr(65)

'A'

ord('b')

98

# 英文字母判斷
str_00 = "D三23安生"

str_00.islower()

False

str_00.isupper()

True

str_00.istitle()

True

# 數字字符判斷
str_00.isdecimal()

False

str_00.isdigit()

False

str_00.isnumeric()

False

# 組合字符判斷
str_00.isalpha()

False

str_00.isalnum()

True

# 其他判斷
str_00.isidentifier()

True

str_00.isspace()

False