入门的时候Python所有 教程都是从第一个hello world开始

print("  hello world ")print()

print是系统内置的一个函数

print(print)     #  print就是一个函数

回顾一个函数定义 f(x,y,z)

def  myfunc():       pass       def  func2(p2, p2):        pass

def :定义函数关键字

myfunc:函数名

fun2(p2,p2): 函数func2有两个参数p1,p2

函数print的定义是怎么样的呢？

def print(self, *args, sep=' ', end='
', file=None): # known special case of print    """    print(value, ..., sep=' ', end='
', file=sys.stdout, flush=False)        Prints the values to a stream, or to sys.stdout by default.    Optional keyword arguments:    file:  a file-like object (stream); defaults to the current sys.stdout.    sep:   string inserted between values, default a space.    end:   string appended after the last value, default a newline.    flush: whether to forcibly flush the stream.    """    pass

 """    print(value, ..., sep=' ', end='
', file=sys.stdout, flush=False)        Prints the values to a stream, or to sys.stdout by default.    Optional keyword arguments:    file:  a file-like object (stream); defaults to the current sys.stdout.    sep:   string inserted between values, default a space.    end:   string appended after the last value, default a newline.    flush: whether to forcibly flush the stream.    """

• print函数支持输出多个数据 print("hello","world") 会输出两个内容，然后以空格分隔

sep: string inserted between values, default a space.

print("hello","world")   # hello world

print("a","b","c",1,[2],True,False)# a b c 1 [2] True False

• 结束符号默认是换行

end: string appended after the last value, default a newline.

print("



")print("abc",end="")  #换行符号为空，不会产生新行。因此abcdef为一行输出print("def")#abcdef

参数与参数之间的分隔符 sep默认是空格

sep: string inserted between values, default a space.

print('hello', 'world', sep='
')  # 这时hello world会分成两行输出helloworld

print('hello', 'world', sep=' -----')hello -----world

print('/home', 'user', 'documents', sep='/')    #    /home/user/documentsprint('', 'home', 'user', 'documents', sep='/')  #   /home/user/documentsprint(1, 'Python Tricks', 'Dan Bader', sep=',')  # node -> child -> childprint('node', 'child', 'child', sep=' -> ')            # 1,Python Tricks,Dan Bader

使用print输出小动画

import timenum_seconds = 3for countdown in reversed(range(num_seconds + 1)):    if countdown > 0:        print(countdown, end='...')        time.sleep(1)    else:        print('Go!')

所以我们用print输出时，可以有很多种选项，不需要

print( "aaa" + str(1))print("abc",1 ) #即可