读取整个文件：

with open('a.txt') as file_object:     file_read = file_object.read()     print(file_read)

f = open('a.txt') print(f.read()) f.close() 逐行读取文件：

file_name = ('a.txt') with open(file_name) as file_object:     for line in file_object:         print(line.rstrip())                   rstrip去除尾部空格

file_name = ('a.txt') with open(file_name) as file_object:     lines = file_object.readlines() for line in lines:     print(line.rstrip())

file_name = ('a.txt') with open(file_name) as file_object:     lines = file_object.readlines() pi_string = '' for line in lines:     pi_string += line.rstrip()     print (len(line)) print(pi_string) print(len(pi_string))

file_name = ('a.txt') with open(file_name) as file_object:     lines = file_object.readlines() pi_string = '' for line in lines:     pi_string += line.strip() print(pi_string[:100] + '...') print(len(pi_string)) 如遇到字符集问题：

with open('a.txt',encoding='utf-8',errors='ignore') as f:     file_object = f.readlines() for line in file_object:     print(line.rstrip()) 写入：

file_name = 'a.txt' with open(file_name,'w',encoding='utf-8') as f:     f.write('i love you')     f.write('\ni love zhangyiyi') 追加到末尾：

file_name = 'a.txt' with open(file_name,'a',encoding='utf-8') as f:     f.write('\ni love you')     f.write('\ni love zhangyiyi') 异常处理:

try:     print(5/0) except ZeroDivisionError:     print("输入错误")

while True:     first_number = input('\nfirst number?:')     if first_number == 'q':         break     second_number = input("second number:")     try:         answer = int(first_number) / int(second_number)     except Exception:         print("错误")     else:         print(answer) 文件异常：

file_name = 'c.txt' try:     with open(file_name,encoding='utf-8') as f:         contents = f.read() except FileNotFoundError:     msg = "文件不存在"     print(msg)