详解Python中的变量及其命名和打印

yipeiwu_com6年前Python基础

在程序中,变量就是一个名称,让我们更加方便记忆。

cars = 100 
space_in_a_car = 4.0 
drivers = 30 
passengers = 90 
cars_not_driven = cars - drivers 
cars_driven = drivers 
carpool_capacity = cars_driven * space_in_a_car 
average_passengers_per_car = passengers / cars_driven 

  

print "There are", cars, "cars available." 
print "There are only", drivers, "drivers available." 
print "There will be", cars_not_driven, "empty cars today." 
print "We can transport", carpool_capacity, "people today." 
print "We have", passengers, "to carpool today." 
print "We need to put about", average_passengers_per_car, "in each car." 


提示:下划线一般用在变量名中表示假想的空格。让变量名的可读性高一点。

运行结果:

root@he-desktop:~/mystuff# python ex4.py 
There are 100 cars available.
There are only 30 drivers available.
There will be 70 empty cars today.
We can transport 120.0 people today.
We have 90 to carpool today.
We need to put about 3 in each car.
root@he-desktop:~/mystuff# 


更多的变量和打印
现在我们输入更多的变量并打印他们,通常我们用""引住的叫字符串。

字符串是相当方便的,在练习中我们将学习怎么创建包含变量的字符串。有专门的方法将变量插入到字符串中,相当于告诉Python:“嘿,这是一个格式化字符串,把变量放进来吧。”

输入下面的程序:

# -- coding: utf-8 -- 
my_name = 'Zed A. Shaw' 
my_age = 35 # 没撒谎哦 
my_height = 74 # 英寸 
my_weight = 180 # 磅 
my_eyes = 'Blue' 
my_teeth = 'White' 
my_hair = 'Brown' 

  

print "let's talk about %s." % my_name 
print "He's %d inches tall." % my_height 
print "He's %d pounds heavy." % my_weight 
print "Actually that's not too heavy." 
print "He's got %s eyes and %s hair." % (my_eyes, my_hair) 
print "His teeth are usually %s depending on the coffee." % my_teeth 


# 下面这行比较复杂,尝试写对它。 
print "If I add %d, %d, and %d I get %d." % ( 
  my_age, my_height, my_weight, my_age + my_height + my_weight) 


提示:如果有编码问题,记得输入第一句。

运行结果:

root@he-desktop:~/mystuff# python ex5.py
let's talk about Zed A. Shaw.
He's 74 inches tall.
He's 180 pounds heavy.
Actually that's not too heavy.
He's got Blue eyes and Brown hair.
His teeth are usually White depending on the coffee.
If I add 35, 74, and 180 I get 289.
root@he-desktop:~/mystuff# 

相关文章

python自定义函数实现一个数的三次方计算方法

python自定义函数实现一个数的三次方计算方法

python自定义函数在运行时,最初只是存在内存中,只有调用时才会触发运行。 def cube_count(a): if is_number(a): return a**...

Python使用lambda表达式对字典排序操作示例

本文实例讲述了Python使用lambda表达式对字典排序操作。分享给大家供大家参考,具体如下: lambda表达式也常用于字典排序,既然写到字典排序,那就把按键排序和按值排序都写写好了...

Django 忘记管理员或忘记管理员密码 重设登录密码的方法

看到标题就知道有逗比忘了密码。。。没错就是我。 你也忘了密码? 不要着急! 0x00: 第一步:运行django shell python3 manage.py shell 0x0...

Python中使用动态变量名的方法

如果要写一个程序,让x1为1,x2为2,然后直到x100为100,你会怎么做? 在C这种静态语言里,变量名这个标识符实际上会被编译器直接翻译成内存地址,所以除了手动设置每个变量的值以外,...

利用Python和OpenCV库将URL转换为OpenCV格式的方法

利用Python和OpenCV库将URL转换为OpenCV格式的方法

今天的博客是直接来源于我自己的个人工具函数库。 过去几个月,有些PyImageSearch读者电邮问我:“如何获取URL指向的图片并将其转换成OpenCV格式(不用将其写入磁盘再读...