这个其实很像Node.js.
读取操作:
python
with open ('./xx.txt', 'r', encoding = 'utf -8') as file:
for i in file:
print(i)
#"file"是个变量, 名称自定, 参数2代表'read', 表明为读取操作.
追加操作:
属于写入的一种,不会重写文档,在原有内容后添加.
python
with open('./xx.txt', 'a+', encoding = 'utf-8') as file:
file.write('写入内容')
何为with:
是一种上下文管理器, with语句管理的代码块执行完毕时, 会自动关闭文件, 这是受推荐的方法,可以确保文件使用完毕后正确关闭. 当然,也可以调用文件对象的close()手动关闭:
可以在读取结构中安插try/finally结构,因为我们也不知道能不能读取成功:
python
file = open('xx.txt', 'r')
try:
file_content = file.read()
print(file_content)
finally:
file.close()
写入操作:
重写所有内容.
python
with open('example.txt', 'w') as file:
file.write('HelloWorld')
写入json:
需要额外模块.
python
import json
json_file_path = 'example.json'
data = { 'name': 'John Doe', 'age': 30 }
with open(json_file_path, 'w')
json.dumps(data) # json对象转字符串
文件重命名:
python
import os
files = os.listdir('path-to-directory') # 获取目录中文件列表
for file in files:
full_path = os.path.join('path-to-directoro', python
if os.path.isfile(full_path) # 检测文件是否存在
new_filename = 'new_name'
os.rename(full_path, os.path.join('path_to_directory', new_filename)) # 旧路径, 新路径
逐行读文件_获取全部行:
python
with open('file.txt', 'r') as file:
lines = file.readlines()
print(lines[0])
逐行读文件_获取单行:
python
with open('file.txt', 'r') as file:
line0 = file.readline()
line1 = file.readline()
创建文件:
python
import os
if not os.path.exists('./aa.txt'):
try:
with open('./aa.txt', 'w') as file
except IOError as error:
print (error)
创建目录:
python
import os
if not os.path.exists('./aadir'):
try:
os.makedirs('./aadir')
except IOError as error:
print (error)
删除文件:
python
import os
if os.path.isfile('./aa.txt')
try:
os.remove('./aa.txt')
except OSError as error:
print(error)