[Python知识库]python编程 从入门到实践 第十章 文件和异常(上)

w (写入模式) a (附加模式) r+(读写模式)，python默认以读写的方式打开文件
文件的读取

with open('text_files/pi.txt') as file_object:
	contents=file_object.read()
print(contents)

显示文件路径时，windows系统使用的时反斜杠()，不是斜杠(/),在代码中使用斜杠（/）,’'属于转义字符

#逐行读取文件
with open('text_files/pi.txt') as file_object:
	for line in file_object:
		print(line)
with open('text_files/pi.txt') as file_object:
	lines=file_object.readlines()
	print(lines)
for line in lines:
	print(line.rstrip())

##练习10-1
with open('learning_python.txt') as file_object:
	print("第一次打印")
	print(file_object.read())
 
	print("第二次打印")
with open('learning_python.txt') as file_object:
	for line in file_object:
		print(line)
 
	print("第三次打印")
with open('learning_python.txt') as file_object:
	lines=file_object.readlines()
for line in lines:
	print(line)
 
"""
第一次打印
In python you can：变量和简单数据类型
In python you can：注释
In python you can：列表
In python you can：if语句
In python you can：字典
In python you can：元组
In python you can：while
In python you can：for
In python you can：函数
In python you can：类文件和异常
第二次打印
In python you can：变量和简单数据类型
In python you can：注释
In python you can：列表
In python you can：if语句
In python you can：字典
In python you can：元组
In python you can：while
In python you can：for
In python you can：函数
In python you can：类文件和异常
第三次打印
In python you can：变量和简单数据类型
In python you can：注释
In python you can：列表
In python you can：if语句
In python you can：字典
In python you can：元组
In python you can：while
In python you can：for
In python you can：函数
In python you can：类文件和异常
"""

#练习10-2
with open('learning_python.txt') as file_object:
	for line in file_object:
		print(line.replace('python','C'))
 
#将python替换成C

写入文件，不是附加

#写入文件
filename='programming.txt'
with open(filename,'r+')as file_object:
	file_object.write('hi,你好哇。')
	read=file_object.read()
	print(read)

附件模式写入文件

filename='programming.txt'
with open(filename,'a+')as file_object:
	file_object.write('hi,你好哇。\n')
	file_object.write('我是flyable\n')
filename='programming.txt'
with open(filename,'r+')as file_object:
	read=file_object.read()
	print(read)

#练习10-3
name=input('请输入你的名字：')
with open('guest.txt','w')as file_project:
	file_project.write(name)

#练习10-4
while True:
	name=input('输入"q"，结束，请输入你的名字:')
	if name=='q':
		break
	else:
		print(f'欢迎{name}的到来！')
		with open('guest_book.txt','a+')as file_project:
			file_project.write(name+'\n')

#练习10-5
while True:
	reason=input('你为什么喜欢编程呢？')
	if reason=='q':
		break
	else:
		with open('resons.txt','a')as file_project:
			file_project.write(reason+'\n')