Python-条件,循环,函数

条件格式:

if 表达式:
    语句1
elif 表达式:
    语句2
elif 表达式:
    语句3
else:
    语句4

循环格式(break,contineu,pass):range特点含左不含右

for name in ["lili","giei","swallow"]:
    print(name) #分行打印出 lili giei swallow


for i in range(1,11):
    print(i) #打印出1~10
else:
    print("for循环结束打印,else可有可无")



while 条件表达式:
    语句1
else:
    语句2 #循环结束时执行一次,可有可无

函数定义:

#函数定义
def func():
    print(1)
    print(2)

def hello(person):
     print("{0},hello".format(person))
     return "return_value" 


def inf_o(name,age):
    print("my name is {0},i am {1} years old.".format(name,age))


def inf_t(name=n,age=a):
    print("my name is {0},i am {1} years old.".format(name,age))

#函数执行:
func()
p="lili"
hello(p)
s=hello(p) #s=return_value

n="swallow"
a=18
inf_o(n,a) #不可以写成inf_o(a,n)
inf_t(name=n,age=a)
inf_t(age=a,name=n)

查找函数文档方法:

help(print) #print函数定义

九九乘法表:

for row in range(1,10):
    #打印一行
    printLine(row)



def printLine(row):
    for col in range(1,row+1)
    print(row*col,end=" ")
    print("-------------")   
    

如果参数不确定不能定义,参数位置也不确定,需要使用收集参数args

def func(*args):
    print("test")
    print(type(args))
    for item in args:
        print(item)



func("swllow",18,"shantou")

关键字收集参数**kwargs

def stu(**kwargs):
    print(type(kwargs))
    for k,v in kwargs.items():
        print(k,"--",v)

stu(name="swallow",age=19,add="shantou")
stu(name="lili") #打印出 name--lili
    

查看函数文档

help(fun_name)
fun_name.__doc__

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转载自blog.csdn.net/Swallow_shangtou/article/details/84866802