python基础【二】

序列类型的内建函数

判断成员是否属于序列

aList = ['Mon', 'Tus', 'Wed', 'Thur', 'Fri', 'Sat', 'Sun']
print('Mon' in aList)      

aList = ['Mon', 'Tus', 'Wed', 'Thur', 'Fri', 'Sat', 'Sun']
print('Mon'not in aList)      

• list：字符串，元组转序列

str = 'Hello World'
a = list(str)
print(a)      

• tuple：字符串,列表转为元组

str = 'Hello World'
a = tuple(str)
print(a)      

• str：

print(type(str(123)))
#<class 'str'>      

• len：长度

aList = ['Mon', 'Tus', 'Wed', 'Thur', 'Fri', 'Sat', 'Sun']
len = len(aList)
print('序列的长度是',len)      

• sorted：排序

aList = [1,4,2,5,6,78,0,9]
a = sorted(aList)
print(a)      

• reversed：逆序排列

aList = [1,4,2,5,6,78,0,9]
a = list(reversed(aList))
#值得注意的地方
print(a)      

• sum:求和

aList = [1,4,2,5,6,78,0,9]
a = sum(aList)
print(a)      

• max:最大值

aList = [1,4,2,5,6,78,0,9]
a = max(aList)
print(a)      

• min：最小值

aList = [1,4,2,5,6,78,0,9]
a = min(aList)
print(a)      

• enumerate：元素加索引

aList = ['Mon', 'Tus', 'Wed', 'Thur', 'Fri', 'Sat', 'Sun']
a = list(enumerate(aList))
print(a)      

• zip：拆分重组

a = 'hello'
b = 'world'
c = list(zip(a,b))
print(c)
#[('h', 'w'), ('e', 'o'), ('l', 'r'), ('l', 'l'), ('o', 'd')]      

字符串的方法

• aStr.center()：宽度居中

aStr = 'hello'
print(aStr.center(15))      

• count(）：判断字符或者子串的个数

aStr = 'hello'
print(aStr.count('l'))      

• find()：返回

aStr = 'hello'
print(aStr.find('lo'))      

• replace：替换某个字符串

= 'hello'
print(aStr.replace('h', "H"))      

• split方法，默认按空格分开这个字符串，返回一个序列

aStr = 'he llo wo rld'
print(aStr.split())
结果：['he', 'llo', 'wo', 'rld']      

• strip()：去掉字符串两端的空格

aStr = ' hello world '
print(aStr.strip())