• 数据结构

数据结构

  1. 列表 list
  2. 字典 dict
  3. 元组 tuple
  4. 集合 set
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list  = [val1,val2,val3,val4]
dict  = {key1:val1,key2:val2}
tuple = (val1,val2,val3,val4)
set   = {val1,val2,val3,val4}

列表 list

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fruit = ['pin','pear']
# 增
fruit.insert(1,'grape') # 1插入位置的前面 如果超过长度则放在最后位置
fruit[0:0] = ['0range']
# 增加多个
fruit.extend(['a','b','c'])
# 删
fruit.remove('grape')
del fruit[0:2]
# 替换
fruit[0] = 'Grapefruit'
# 不能使用值直接调用
fruit['H']

字典 dict

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NASDAQ_code = {
 'BIDU':'Baidu',
 'SINA':'Sina'
}
# 增
NASDAQ_code['YOKU'] = 'Youku'
# 增加多个
NASDAQ_code.update({'FB':'Facebook','TSLA':'Tesla'})
# 删
del NASDAQ_code['FB']

元组

不可修改,只能获取

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letters = ('a','b','c','d','e','f','g')
letter[0]

集合

无序的不重复的
不能切片也不能被索引

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a_set = {1,2,3,4}
# 增
a_set.add(5)
# 删
a_set.discard(5)

列表排序

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list = [6,2,7,4,1,3,5]
# 排序
print(sorted(list))
# 逆序
print(sorted(list,reserve=True))

同时处理两个列表

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num = [6,7,5,2,3]
str = ['d','t','a','e','b','y']

for a,b in zip(num,str):
    print(a,'-',b)

推导式(解析式)

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# 原形
a = []
for i in range(1, 11):
    a.append(i)
print(a)
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# 推导式 提高效率
a = [i**2 for i in range(1, 11)]
print(a)
b = [i + 1 for i in range(1, 11)]
print(b)
c = [i for i in range(1, 11) if i % 2 == 0]
print(c)
z = [letter.lower() for letter in "ABCDEFG"]
print(z)
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# 字典推导式
d = {i:i+1 for i in range(4)}
print(d)
e = {i:j for i,j in zip(range(1,6),'abcde')}
print(e)
f = {i:j.upper() for i,j in zip(range(1,6),'abcde')}
print(f)

获取列表索引

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letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
for num,letter in enumerate(letters):
    print(letter,'is',num+1)