条件表达式:
if 1>2:print(111)
elif 2>3:print(222)
else:print(333)
for循环:
for i in range(3,10):
print(i)
输出结果:for循环,步长为2
for i in range(1,10,2):
print(i)
输出结果:
想打印到一行的话,print加一个end参数,如:print(i,end="")即可
打印引用内容:
name = "王路飞"
s = f"我是海贼{name}"
print(s)
结果:
反转字符串:
s = "123456"
print(s[::-1])
结果:
去除字符串前后空格:
username = " admin "
realrm= username.strip();
print(realrm)
print(len(username))
print(len(realrm))
结果:
修改变量:
"""
global:局部修改全局变量
nonlabal:在局部引入外层的局部变量
"""
a = 10
def func():
global a #修改全局变量需要global
a = 20
func()
print(a)
def func1():
a = 10
def func2():
nonlocal a #向上一层找有没有该变量,没有继续向上一层找,直到最外层(不到全局)
a = 20
func2()
print(a)
func1()
结果:20
20
数组添加移除元素:
list = []
list.append("aaa")
list.append("bbb")
list.insert(1,"111") #指定位置插入指定的字符串
print(list)
result = list.pop(1) #移除下标为1的字符串
print(list) #打印移除后的list
print(result) #打印移除的字符
结果:
数组循环:
list=["1a","2b","3c"]
for i in range(len(list)):#循环0-list长度的的下标
print(i,end="")
print()
for item in list:#循环list中的元素
print(item,end="")
结果:
字典取值遍历:
dict = {"key":1,"key2":"11"}
print(dict.get("key"))
print(dict["key2"])
#遍历字典
for key in dict :#遍历key,根据key拿vaules
print(key,dict.get(key))
print(list(dict.keys()))#拿到所有的key
for key,values in dict.items():
print(key,values)
结果:
元素互换位置:
a = 10
b = 20
a,b = b,a
print(a)
print(b)
结果: 20
10
判断元素出现次数:
lst = ["a","b","c","a","a"]
print(lst.count("a"))
结果:3
计算从0-100的和:
print(sum(range(0,101)))
结果:5050
打印99乘法表:
def write99():
for i in range(1, 10):
for j in range(1, i+1):
print(f"{i}*{j}={i*j}",end=" ")
print()
write99()
结果:
从小到大排序:
def bigToSimal(arr):
for i in range(1,len(arr)):
for j in range(0,len(arr)-i):
if arr[j] < arr[j+1]:
temp = arr[j+1]
arr[j+1] = arr[j]
arr[j] = temp
return arr
arra = [2, 5, 8, 1, 3]
print(bigToSimal(arra))
结果:[8, 5, 3, 2, 1]
装饰器:
def guanjia(game):
def inner():
print("打开科技")
game()
print("关闭科技")
return inner
@guanjia
def play_hali():
print('hello,hali')
@guanjia
def play_ys():
print("向着星辰与深渊")
play_ys()
结果:打开科技
向着星辰与深渊
关闭科技
# 通用装饰器写法
def wrapper(fn): #fn:目标函数
def inner(*args,**kwargs):
ret = fn(*args,**kwargs)
return ret
return inner