【原创】python学习笔记（4）--《笨办法学python》，print函数相关

额外注意：block在python这里很严格重要

不规范缩进,block会报错！

一 print函数的版本差异

（1）py2里可以不带括号，如 print "hello world"

        PY2里写print ("hello" ,"world") 会输出 ("hello" ,"world")   #被认识是元组，但1个字符串不会

（2）py3里必须是函数形式，

        PY3里写必须写成print ("hello" ,"world") 会输出 "hello" ,"world"

print"let me have test on you,ok or not?"
user_option=raw_input()
if user_option=="ok":
	print"enter your name"
	user_name=raw_input()
	user_password=raw_input("enter your password:\n")
	user_age = raw_input("enter your age\n")
	user_confirm=raw_input("are you ok?enter ok or not:\n")
	if user_confirm == "ok":
		print ("hello",user_name,"your password is:",user_password)
		print ("you were born in ",2018-int(user_age))
	else:
		print ("quit")	
else:
	print "compare some cals"

        print "hello" "world"
        print ("hello" "world")

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


        print "7/4 is",7/4
	print "7.0/4.0 is",7.0/4.0

二 print 多个参数

print 可以支持打印多个字符串等，中间以,分隔

print在一行结尾的,不是分隔符，而是表示，这个print执行完后，不处理\n,也就是不进行分行

三 print 与格式控制符号

有中文记得开头输入这个，否则报错   # -*- coding:utf-8 -*-

print("your name and age is %s %s")   %(your_name,your_age),

注意有多个格式化符号%时，和后面不加符号分隔，只空格，然后，%要括号，并且注意括号前后的空格！！

# -*- coding:utf-8 -*-
# "你好"
# 你好
# nihao
print ("hello","rhino1")

my_name="rhino2"
print ("hello",my_name)

my_name="rhino3"
my_type="big"
num=1


print ("hello %s") %my_name
print ("there is 1 %s") %my_name
print ("there is %d rhino3") %num


print ("there is 1 %s %s") %(my_type,my_name)
print ("there is %d %s") %(1,my_name)
print ("there is %d %s") %(1,"rhino3")
print ("there is %d %s") %(num,my_name)
print  "there is %d %s" % (num,my_name) 


#"reference应用在不区分是decimal还是string的地方" %r  
#your_name=raw_input("请输入你的名字\n")              #加了UTF8之后不会报错了，但是仍然显示不正常？
#your_age=raw_input("请输入你的年纪\n")              #加了UTF8之后不会报错了，但是仍然显示不正常？
your_name=raw_input("enter your name\n")            
your_age=raw_input("enter your age\n")            



print("your name and age is ",your_name,your_age)
#print("your name and age is %s %d") %(your_name,your_age)        #注意，raw_input()导入的都是字符串类型的，要转
#print("your name and age is %d %d") %(your_name,int(your_age))   #数据类型不用对会报错
print("your name and age is %s %d") %(your_name,int(your_age))    #用户年龄输入数字不会出错，但乱填就会还是报错。
#可以要求输入的必须是某格式，或者强转的，我记得


print("your name and age is %s %s") %(your_name,your_age)
print("your name and age is %r %r") %(your_name,your_age)         # 这个可以保证用户不按照实际输入也不报错
print("ok")



# 我很容易写错的，%d %s %r 而不是 d% s%等等 ，要记住%像\一样，都是要写在前面！！！

四 其他print，如pprint

注意，需要使用前，先import pprint

message='It was a bright cold day in April,and the clocks were striking thirtenn.'
count={}
for character in message:
	count.setdefault(character,0)
	count[character]=count[character]+1
print(count)

import pprint
message='It was a bright cold day in April,and the clocks were striking thirtenn.'
count={}
for character in message:
	count.setdefault(character,0)
	count[character]=count[character]+1
print(count)
pprint.pprint(count)

message='It was a bright cold day in April,and the clocks were striking thirtenn.'
count={}
for character in message:
	count.setdefault(character,0)
	count[character]=count[character]+1
print(count)
pprint.pformat(count)

输出结果是如下