(1) Python 数据类型功能

1.int

将字符串转化为数字

a="123"  print(type(a),a)

b=int(a)  print(type(b),b)

num="0011" int(num,base=2)  #8,16

2.bit_length

当前数字的二进制至少用几位来表示

age=4
   r=age.bit_length()
   print(r)

3.str

test = "OPenoekndOO GT"
v=test.capitalize()
print(v)
v1=test.casefold()
print(v1)
v2=test.lower()
print(v2)
v3=test.center(20,"*")
print(v3)
v4=test.count('O',6,14)
print(v4)
#encode
#decode
v5=test.endswith("T")
print(v5)
v6=test.startswith("O")
print(v6)
v6=test.find("e",3,10)
print(v6)
test='i am {name},age {a}'
v=test.format(name='alex',a=19)
print(v)
test='i am {0},age {1}'
v=test.format('terry',22)
print(v)
test='i am {name},age {age}'
v=test.format_map({"name":'tianxiongfie',"age":22})
print(v)
test="uad891"
v=test.isalnum()
print(v)
#True