《笨办法学Python3》练习五：更多变量和练习

练习代码

my_name = 'Zed A. Shaw'
my_age = 35 # not a lie
my_height = 74 # inches
my_weight = 180 # lbs
my_eyes = 'Blue'
my_teeth = 'White'
my_hair = 'Brown'

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

# This line is tricky, try to get it exactly right
total = my_age + my_height +  my_weight
print(f"If I add {my_age}, {my_height}, and {my_weight} I get {total}.")

Study Drills

1. Change all the variables so there is no my_ in front of each one. Make sure you change the name everywhere, not just where you used = to set them.

name = 'Zed A. Shaw'
age = 35 # noyt a lie
height = 74 # inches
weight = 180 # lbs
eyes = 'Blue'
teeth = 'White'
hair = 'Brown'

print(f"Let's talk about {name}.")
print(f"He's {height} inches tall.")
print(f"He's {weight} pounds heavy.")
print("Actually that's not too heavy.")
print(f"He's got {my_eyes} eyes and {hair} hair.")
print(f"His teeth are usually {teeth} depending on the coffee.")

# this line is tricky, try to get it exactly right
total = my_age + my_height +  my_weight
print(f"If I add {age}, {height}, and {weight} I get {total}.")

2. Try to write some variables that convert the inches and pounds to centimeters and kilograms.
   Do not just type in the measurements. Work out the math in Python.

my_name = 'Zed A. Shaw'
my_age = 35 # noyt a lie
my_height = 74 # inches
my_height =  my_height * 2.54 # centimeters
my_weight = 180 # lbs
my_weight = my_weight * 0.4535924 # kilograms
my_eyes = 'Blue'
my_teeth = 'White'
my_hair = 'Brown'

print(f"Let's talk about {my_name}.")
print(f"He's {my_height} centimeters tall.")
print(f"He's {my_weight} kilograms heavy.")
print("Actually that's not too heavy.")
print(f"He's got {my_eyes} eyes and {my_hair} hair.")
print(f"His teeth are usually {my_teeth} depending on the coffee.")

# this line is tricky, try to get it exactly right
total = my_age + my_height +  my_weight
print(f"If I add {my_age}, {my_height}, and {my_weight} I get {total}.")

补充

1. 使用round()函数精确浮点数

官方文档描述

举例：

num = 1682.675

print(round(num)) # 第二个参数省略时，返回整数
print(round(num, 0)) # 精确到个位，1683.0
print(round(num, 1)) # 十分位，1683.7
print(round(num, 2)) # 百分位1683.67 因为计算机显示精度的原因，不是 1683.68
print(round(num, -1)) # 十位
print(round(num, -2)) # 百位

print(round(-0.5))
print(round(0.5)) # 特殊