（读书笔记）笨办法学python-（习题1-40）

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习题11:提问

age = input("How old are you?")
height = input("How tall are you?")
weight = input("How much do you weigh?")
print ("So, you're %r old, %r tall and %r heavy." %(age, height, weight))

输出结果为

How old are you?35
How tall are you?180
How much do you weigh?140
So, you're '35' old, '180' tall and '140' heavy.

问题15、16、17：文件的读写操作

问题20：函数和文件

from sys import argv

script, input_file = argv

def print_all(f):
	print (f.read())
	
def rewind(f):
	f.seek(0)
	
def print_a_line(line_count, f):
	print (line_count, f.readline())

#打开文件	
current_file = open(input_file，encoding = 'utf-8')

#展示文件全部内容
print ("First let's print the whole file:\n")
print_all(current_file)

#重新定义展示文章行号
print ("Now let's rewind, kind of like a tape.")
rewind(current_file)

#展示文件的前三行内容
print ("Let's print three lines:")
current_line = 1 #设置开始行行号
print_a_line(current_line, current_file)
current_line = current_line + 1
print_a_line(current_line, current_file)
current_line = current_line + 1
print_a_line(current_line, current_file)

输出结果为

First let's print the whole file:
To all the people out there.
I say I don't like my hair.
I need to shave it off.

Now let's rewind, kind of like a tape.

Let's print three lines:
1 To all the people out there.
2 I say I don't like my hair.
3 I need to shave it off.

习题21：函数可以返回东西

def add(a, b):
    print ("ADDING %d + %d" % (a, b))
    return a + b

def subtract(a, b):
    print ("SUBTRACTING %d - %d" % (a, b))
    return a - b

def multiply(a, b):
    print ("MULTIPLYING %d * %d" % (a, b))
    return a * b

def divide(a, b):
    print ("DIVIDING %d / %d" % (a, b))
    return a / b

print ("Let's do some math with just functions!")
age = add(30, 5)
height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)
print ("Age: %d, Height: %d, Weight: %d, IQ: %d" % (age, height,weight, iq))

print('\n')#换行符

# A puzzle for the extra credit, type it in anyway.
print ("Here is a puzzle.")
what = add(age, subtract(height, multiply(weight, divide(iq,2))))
print ("That becomes: ", what, "\n  Can you do it by hand?")

输出结果为

Let's do some math with just functions!
ADDING 30 + 5
SUBTRACTING 78 - 4
MULTIPLYING 90 * 2
DIVIDING 100 / 2
Age: 35, Height: 74