《python编程：从入门到实践》答案（第十章）

布满荆棘的人生 2022-12-10 07:12 139阅读 0赞

### 第十章 ###

![20200924152322524.png][]

with open("learning_python.txt") as file_object:
    	contents=file_object.read()
    	print(contents)

with open("learning_python.txt") as file_object:
    	for line in file_object:
    		print(line.rstrip())

contents=''
    with open("learning_python.txt") as file_object:
    	lines=file_object.readlines()
    for line in lines:
    	print(line.rstrip())

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NodXl1ZGV4aWFvd3U_size_16_color_FFFFFF_t_70][]

contents=''
    with open("learning_python.txt") as file_object:
    	lines=file_object.readlines()
    for line in lines:
    	line=line.replace('python','C')
    	print(line.rstrip())

![20200924170227636.png][]

name=input("Please enter your name: ")
    file_name='guest.txt'
    with open(file_name,'a') as file_object:
    	file_object.write(name+"\n")
    with open(file_name) as need_read:
    	lines=need_read.readlines()

![20200924170250161.png][]

file_name='guest.txt'
    while(True):
    	name=input("Please enter your name: ")
    	if name!='quit':
    		with open(file_name,'a') as file_object:
    			file_object.write(name+"\n")
    	else:
    		break

![20200924170820504.png][]

file_name='reason.txt'
    while(True):
    	reason=input("Why you love programming ? ")
    	if reason!='quit':
    		with open(file_name,'a') as file_object:
    			file_object.write(reason+'\n')
    	else:
    		break
    
    with open(file_name) as need_r:
    	lines=need_r.readlines()
    for line in lines:
    	print(line.rstrip())

### ![20200925160406489.png][] ###

try:
    	num_1=input("Please enter the first number: ")
    	x=int(num_1)
    		
    	num_2=input("Please enter the second number: ")
    	y=int(num_2)
    except ValueError:
    	print("your input is not a number,try again.")
    else:
    	print(x+y)

![20200925161350531.png][]

print("Please enter two numbers.\n")
    print("Enter 'q' to quit.")
    while True:
    	try:
    		num_1=input("Please enter the first number: ")
    		if num_1=='q':
    			break
    		x=int(num_1)
    		
    		num_2=input("Please enter the second number: ")
    		if num_2=='q':
    			break
    		y=int(num_2)
    	except ValueError:
    		print("your input is not a number,try again.")
    	else:
    		print(x+y)

![20200925162133297.png][]

file_name='dogs.txt'
    try:
    	with open(file_name) as f:
    		contents=f.read()
    except FileNotFoundError:
    	print("Tis file does not exist.")
    else:
    		print(contents)

![20200925165819162.png][]

file_name='dogs.txt'
    try:
    	with open(file_name) as f:
    		contents=f.read()
    except FileNotFoundError:
    	pass
    else:
    		print(contents)

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NodXl1ZGV4aWFvd3U_size_16_color_FFFFFF_t_70 1][]

try:
    	with open('alice.txt') as f:
    		contents=f.read()
    except FileNotFoundError:
    	print("sorry ,this file does not exit.")
    else:
    	words_num=contents.lower().count('the')
    	print(words_num)

![20200926081842893.png][]

import json
    fav_num=input("Enter your favorite number: ")
    file_name="favnum.json"
    with open(file_name,'w') as f:
    	json.dump(fav_num,f)
    with open(file_name) as f:
    	num=json.load(f)
    	print("I know your favorite number! It's "+num+".")

![20200926081910779.png][]

import json
    
    def get_favnum():
    	file_name="favnum.json"
    	try:
    		with open(file_name) as f:
    			num=json.load(f)
    	except FileNotFoundError:
    		return None
    	else:
    		return num
    def print_favnum():
    	num=get_favnum()
    	if num:	
    		print("I know your favorite number! It's "+num+".")
    	else:
    		file_name="favnum.json"
    		num=input("Enter your favorite number: ")
    		with open(file_name,'w') as f:
    			json.dump(num,f)
    print_favnum()

![20200926100135266.png][]

![20200926100149990.png][]

import json
    
    def get_sorted_user():
    	'''获取存储的用户名'''
    	file_name="username.json"
    	try:
    		with open(file_name) as f:
    			user_name=json.load(f)
    	except FileNotFoundError:
    		return None
    	else:
    		return user_name
    
    def get_new_user():
    	'''获取新的用户名'''
    	user_name=input("Enter your name: ")
    	file_name="username.json"
    	with open(file_name,'w') as f:
    		json.dump(user_name,f)
    	return user_name
    
    def greet():
    	'''问候用户并指出名字'''
    	user=get_sorted_user()
    	if user:
    		print("Welcome "+user+"~")
    		ask=input("Am I right? Enter 'y' or 'no': ")
    		if ask=='y':
    			pass
    		elif ask=='n':
    			user=get_new_user()
    			print("Welcome "+user+"~")
    	else:
    		user=get_new_user()
    		print("Welcome "+user+"~")
    greet()

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[20200924170227636.png]: /images/20221123/d6fcb29c6c554786b39be6fff17016c9.png
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[20200924170820504.png]: /images/20221123/d17f5e26369e4e7f89d5ea3911af1bcf.png
[20200925160406489.png]: /images/20221123/ed866b5755254c39ab79485fb4f63ed3.png
[20200925161350531.png]: /images/20221123/6ab0cfd03b584566b1186b96590271b2.png
[20200925162133297.png]: /images/20221123/c61e2a4ae2d845f597c4b3ba4d8f6788.png
[20200925165819162.png]: /images/20221123/61a017f6bd6a4d85b00292938bd00ebd.png
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[20200926081842893.png]: /images/20221123/ba75c0a9dcd643d7a49d646b4cbbdf87.png
[20200926081910779.png]: /images/20221123/70601fe54fbe4ef5b2ef250645124b8b.png
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[20200926100149990.png]: /images/20221123/1aca62add4fd47e6917fb065bf8bea19.png