写操作

./1/write.py

content = "Python is the most popular language"
with open("test.txt", "w") as f:
    f.write(content)

~$ cd ./1
~/1$ python write.py

读操作

./1/read.py

with open("test.txt") as f:
    print(f.read())

~$ cd ./1
~/1$ python read.py
Python is the most popular language

中文的读写

./1/writeChinese.py

content = "Python是当下最流行的语言"
with open("chinese.txt", "w", encoding='utf-8') as f:
    f.write(content)

./1/readChinese.py

with open("chinese.txt", encoding='utf-8') as f:
    print(f.read())

~$ cd ./1
~/1$ python writeChinese.py
~/1$ python readChinese.py
Python是当下最流行的语言

./1/chinese.txt

Python是当下最流行的语言

读写模式

模式	含义
r(default)	只读
w	只写。若文件已存在，则覆盖原文件的内容
x	以只读方式创建新文件。若文件已存在，则抛出`FileExistsError`错误
a	以追加方式打开文件。若文件已存在，在其尾部追加数据。若文件不存在，创建新文件
rb	二进制只读
wb	二进制只写。若文件已存在，则覆盖原文件的内容
xb	以二进制只读方式创建新文件。若文件已存在，则抛出`FileExistsError`错误
ab	以二进制追加方式打开文件。若文件已存在，在其尾部追加数据。若文件不存在，创建新文件
r+/rb+/w+/wb+/x+/xb+/a+/ab+	以读写方式打开，其他的含义见上。如a是以写追加方式打开，而a+是以读写追加方式打开

json文件的读写操作

./1/writeJson.py

import json

data = {
    "name": "Bertramoon",
    "sex": "male"
}
# json.dumps()方法将Python的dict类转化为json字符串
with open("testJson.json", "w") as f:
    f.write(json.dumps(data))

./1/readJson.py

import json

with open("testJson.json") as f:
    data = json.loads(f.read())
    print(type(data))
    [print(f"{key}: {value}") for key, value in data.items()]

~$ cd ./1
~/1$ python writeJson.py
~/1$ python readJson.py
<class 'dict'>
name: Bertramoon
sex: male

./1/testJson.json

{"name": "Bertramoon", "sex": "male"}

你可能觉得写入的排版不是很喜欢，而且json对象有时候有中文。那么，接下来我们再演示一个样例吧

./1/writeJsonChinese.py

import json

data = {
    "university": "北京大学",
    "city": "北京市"
}
# json.dumps()方法将Python的dict类转化为json字符串
with open("testJsonChinese.json", "w", encoding='utf-8') as f:
    # indent代表缩进的字符数，控制排版。ensure_ascii表示是否编码形式存储，如果False的话，则会以我们所见的中文形式（字符集）存储
    f.write(json.dumps(data, indent=4, ensure_ascii=False))

./1/readJsonChinese.py

import json

with open("testJsonChinese.json", encoding='utf-8') as f:
    data = json.loads(f.read())
    print(type(data))
    [print(f"{key}: {value}") for key, value in data.items()]

~$ cd ./1
~/1$ python writeJsonChinses.py
~/1$ python readJsonChinese.py
<class 'dict'>
university: 北京大学
city: 北京市

./1/testJsonChinese.json

{
    "university": "北京大学",
    "city": "北京市"
}

yaml文件的读写操作

./1/writeYaml.py

import yaml
from datetime import date


class Student(object):
    def __init__(self, no, name, age):
        self.no = no
        self.name = name
        self.age = age


data = {
    'student': [
        Student('1', '张三', '22'),
        Student('2', '李四', '21')
    ],
    'university': '北京大学',
    'city': '北京市',
    'today': date.today()
}
with open("testYaml2.yml", "w", encoding='utf-8') as f:
    f.write(yaml.dump(data, allow_unicode=True))

./1/readYaml.py

import yaml


class Student(object):
    def __init__(self, no, name, age):
        self.no = no
        self.name = name
        self.age = age

    def __str__(self):
        return f"{self.no} - {self.name} - {self.age}"


with open("testYaml2.yml", encoding='utf-8') as f:
    config = yaml.unsafe_load(f)
    print(type(config))
    [print(f"{key} {type(value)}: {value}") for key, value in config.items()]
    [print(item) for item in config['student']]

~$ cd ./1
~/1$ python writeYaml.py
~/1$ python readYaml.py
<class 'dict'>
city <class 'str'>: 北京市
student <class 'list'>: [<__main__.Student object at 0x000001712EFE4370>, <__main__.Student object at 0x000001712EFE43D0>]
today <class 'datetime.date'>: 2021-05-09
university <class 'str'>: 北京大学
1 - 张三 - 22
2 - 李四 - 21