太久没动程序了，参加Kaggle:Predict Future Sales，顺便将之前学的快速复习一下，在此做个摘抄笔记。

Python print()函数生成Loading….

语法

以下是 print() 方法的语法:

print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

参数

objects – 复数，表示可以一次输出多个对象。输出多个对象时，需要用 , 分隔。
sep – 用来间隔多个对象，默认值是一个空格。
end – 用来设定以什么结尾。默认值是换行符 \n，我们可以换成其他字符串。
file – 要写入的文件对象。
flush – 输出是否被缓存通常决定于 file，但如果 flush 关键字参数为 True，流会被强制刷新。

import time
print("---RUNOOB EXAMPLE ： Loading 效果---")
print("Loading",end = "")
for i in range(20):
    print(".",end = '',flush = True)
    time.sleep(0.5)

来源：https://www.runoob.com/python3/python-func-print.html

help()函数显示自建函数说明

看程序一目了然：

def least_difference(a, b, c):
    diff1 = abs(a - b)
    diff2 = abs(b - c)
    diff3 = abs(a - c)
    return min(diff1, diff2, diff3)
    
help(least_difference)
>>Help on function least_difference in module __main__:
least_difference(a, b, c)
#j加上函数注释
def least_difference(a, b, c):
    """Return the smallest difference between any two numbers
    among a, b and c.
    
    >>> least_difference(1, 5, -5)
    4
    """
    diff1 = abs(a - b)
    diff2 = abs(b - c)
    diff3 = abs(a - c)
    return min(diff1, diff2, diff3)
    
help(least_difference)
>>Help on function least_difference in module __main__:
least_difference(a, b, c)
    Return the smallest difference between any two numbers
    among a, b and c.
    
    >>> least_difference(1, 5, -5)
    4

总结：加了注释的函数使用help()会展现说明(即函数本身注释说明)。

max()函数调用自建函数

def mod_5(x):
    """Return the remainder of x after dividing by 5"""
    return x % 5
print(
    'Which number is biggest?',
    max(100, 51, 14),
    'Which number is the biggest modulo 5?',
    max(100, 51, 14, key=mod_5),
    sep='\n',
)
>>
Which number is biggest?
100
Which number is the biggest modulo 5?
14

来源：https://www.kaggle.com/colinmorris/functions-and-getting-help

字符串易冲突点

What you type...	What you get	example		print(example)
	\'	 			   '			'What\'s 	    What's up?      	
	\"				   "		"That's \"cool\" 	That's "cool"
	\\				   \	   "A mountain: /\\"	A mountain: /\
	\n							"1\n2 3"			1
												    2 3
												    
hello = "hello\nworld" 对等 triplequoted_hello = """hello
world"""

str.split()相反对等str.join()

datestr = '1956-01-31'
year, month, day = datestr.split('-')
>>
1956 01 31
'/'.join([month, day, year])
>>
'01/31/1956'

str.format()多种展示方法

#直接调用
"{}, you'll always be the {}th planet to me.".format(planet, position)
#切片调用，可配合运算符等
"{} weighs about {:.2} kilograms ({:.3%} of Earth's mass). It is home to {:,} Plutonians.".format(
    planet, pluto_mass, pluto_mass / earth_mass, population,
)
#索引调用
s = """Pluto's a {0}.
No, it's a {1}.
{0}!
{1}!""".format('planet', 'dwarf planet')
print(s)

来源：https://www.kaggle.com/colinmorris/strings-and-dictionaries

待续….