Python开发IDE(Integrated Development Environment):
PyCharm、Eclipse
1.Python运算符
运算结果是值
1.算术运算
a = 10 * 10
print(a)
100
2.赋值运算
a = 11
a = a + 1 或 a += 1
print(a)
12
运算结果是布尔值
1.比较运算
a = 1 > 5
print(a)
False
2.逻辑运算
a = 1 > 6 or 1 == 1
print(a)
True
3.成员运算
a = "老土" in "疯狂坦克"
print(a)
False
2.Python基本数据类型
数值型 int 所有功能都放在int里
a1 = 123
a1 = 456
print(a1)
456
- int
字符串转换为数字
a = "123"
print(type(a),a)
str 123
b = int(a)
print(type(b),b)
int 123
num = "0011"
v = int(num,base=16)
print(v)
- bit_length
#当前数字的二进制,至少用n位表示
r = age.bit_length()
字符串 str
s1 = "welcome"
s2 = "hello"
#首字母大写
name = "ocean"
v = name.capitalize()
print(v)
#所有字符转换为小写,casefold很厉害,很多位置的对相应转换小写
v1 = name.casefold()
print(v1)
v2 = name.lower()
print(v2)
#设置宽度,并将内容居中
10代表总长度
*填充空白位置
v3 = name.center(10,"中")
print(v3)
****中****
#搜寻字符串中的关键字,计算子序列的出现次数
name = "ocaenoceaneanaenn"
v4 = name.count('ea')
print(v4)
2
name = "ocaenoceaneanaenn"
v5 = name.count('ea',4,9)
print(v5)
1
#字符串开始、字符串结尾
name = "ocean"
v6 = name.endswith('oc')
v7 = name.startswith('oc')
print(v6)
print(v7)
False
True
#字符串由左向右,搜寻子序列之后,输出位置
name = "oceanocean"
v8 = name.find('ce')
print(v8)
#index找不到,报错
name = "ocaenocaen"
v9 = name.index(6)
print(v9)
#格式化,讲一个字符串中的占位符替换成指定的值
name = 'i am {bb}, age{aa}'
print(name)
v10 = name.format(bb='ocean',aa=18)
print(v10)
#格式化,传入的值 {"bb":'ocean',"aa":18}
name = 'i am {bb}, age{aa}'
v11 = name.format(name='dd',a=1-)
v12 = name.format_map({"bb":'ocean',"aa":18})
#字符串中是否包含 字母或数字
name = "123"
v13 = name.isalnum()
print(v13)