Python 基础语法

 

 

Python 基础语法

基础语法

运行结果

数学运算符

a = 20
b = 3

print(a % b)
print(a // b)
print(a ** b)

2
6
8000

逻辑操作符

a = 20
b = 3
c = 10

print ( a>b or a>c  )
print ( a>b and a>c  )
print (not a > b  )

True
True
False

成员运算符
（返回结果是布尔类型）

list = [12, 23, 454, 'hello', True, 22]

print(454 in list)
print(45 in list)

True
False

身份运算符

a = 9
b = 10
print (a+1 is b)
print (a is b)
print (a+1 is not b)
print (a is not b)

True
False
False
True

条件判断 if else (1)

a= 10

if a < 5:
    print("small")
elif a < 8:
    print("medium")
else:
    print("big")

big

条件判断 if else (2)

# a = []
# a = ()
# a=""
# a= None
 a = {}

if a:
    print("ture")
else:
    print("false")

FALSE

循环while

a = 1

while a < 10:
    print(a)
    a+=2

1
3
5
7
9

遍历for (1)

list = [123, 'hello', 3+2, 8.8, 'aa']

for x in list:
    print(x)

123
hello
5
8.8
aa

遍历for (2)
range(start, stop[, step]) -> range object

list = range(1, 10, 3)
for x in list:
    print(x)

1
4
7

跳出循环 (1)

a = range(1, 10)

for x in a:
    if x % 2 == 0:
        continue
    else:
        print(x)
print("-----------")

for x in a:
    if x % 2 == 0:
        break
    else:
        print(x)

1
3
5
7
9
-----------
1

跳出循环 (2)

a = range(1, 10)
for x in a:
    if x % 2 == 0:
        break
    else:
        print(x)
else:
    print('ok')

1

跳出循环 (3)

a = range(1, 10)
for x in a:
    if x % 2 == 0:
       continue
    else:
        print(x)
else:
    print('ok')

1
3
5
7
9
ok