详解Python中的变量及其命名和打印

yipeiwu_com7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

PyQt5图形界面播放音乐的实例

安装Pygame pip install pygame import time import pygame pygame.init() print("播放音乐1") track =...

Python正确重载运算符的方法示例详解

前言 说到运算符重载相信大家都不陌生,运算符重载的作用是让用户定义的对象使用中缀运算符(如 + 和 |)或一元运算符(如 - 和 ~)。说得宽泛一些,在 Python 中,函数调用(()...

使用TensorFlow实现二分类的方法示例

使用TensorFlow实现二分类的方法示例

使用TensorFlow构建一个神经网络来实现二分类,主要包括输入数据格式、隐藏层数的定义、损失函数的选择、优化函数的选择、输出层。下面通过numpy来随机生成一组数据,通过定义一种正负...

Python中enumerate函数代码解析

enumerate函数用于遍历序列中的元素以及它们的下标。 enumerate函数说明: 函数原型:enumerate(sequence, [start=0]) 功能:将可循环序列...

Python3实现的回文数判断及罗马数字转整数算法示例

本文实例讲述了Python3实现的回文数判断及罗马数字转整数算法。分享给大家供大家参考,具体如下: 回文数 判断一个整数是否是回文数。回文数是指正序(从左向右)和倒序(从右向左)读都是一...