Day 24 - 文件、目录与路径 - Python学习笔记

Udemy - 100 Days of Code: The Complete Python Pro Bootcamp

Day 24 - Intermediate - Files, Directories and Paths

- - - [182. Add a High Score to the Snake Game](#182. Add a High Score to the Snake Game)
    - [183. Open, Read and Write Files](#183. Open, Read and Write Files)
    - [184. Read and Write the High Score to a File](#184. Read and Write the High Score to a File)
    - [185. Relative and Absolute File Paths](#185. Relative and Absolute File Paths)
    - [186. Mail Merge Project](#186. Mail Merge Project)

182. Add a High Score to the Snake Game

python 复制代码

class Scoreboard(Turtle):  
    def __init__(self):  
        super().__init__()  
        self.score = 0  
        self.high_score = 0  
        self.color("white")  
        self.hideturtle()  
        self.penup()  
        self.goto(0, 260)  
        self.update_scoreboard()  
    
    def update_scoreboard(self):  
        self.clear()  
        self.write(f"Score: {self.score} High Score: {self.high_score}", align=ALIGNMENT, font=FONT)  
    
    def increase_score(self):  
        self.score += 1  
        self.update_scoreboard()  
    
    def reset(self):  
        if self.score > self.high_score:  
            self.high_score = self.score  
        self.score = 0  
        self.update_scoreboard()


class Snake:
    ...
    def reset(self):  
        for seg in self.segments:  
            seg.goto(1000, 1000)  
        self.segments.clear()  
        self.create_snake()  
        self.head = self.segments[0]


# Detect collision with wall  
if (snake.head.xcor() > 280 or snake.head.xcor() < -280 or  
    snake.head.ycor() > 280 or snake.head.ycor() < -280):  
    scoreboard.reset()  
    snake.reset()  
  
# Detect collision with tail  
for segment in snake.segments[1:]:  
    if snake.head.distance(segment) < 10:  
        scoreboard.reset()  
        snake.reset()

183. Open, Read and Write Files

读写文件

Open

open(file, mode='rt', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

参数说明
file：文件路径或文件描述符
mode：打开模式

"r" 读取模式（默认），"w" 覆盖模式，"a" 追加模式，"x" 独占创建

"t" 文本模式（默认），"b" 二进制模式

"+" 可读可写

buffering：缓冲策略

0 无缓冲（仅二进制模式）

1 行缓冲（仅文本模式）

>1 指定缓冲区大小（字节）

-1 系统默认缓冲策略

encoding：编码格式（仅文本模式）（如 utf-8，gbk，ascii）
errors: 编码报错方式（仅文本模式）（如 "strict" 直接报错， "ignore" 忽略错误字符， "replace" 替换成 �）
newline：换行符设置（仅文本模式）（None，""，"\n"，"\r"，"\r\n"）

closefd：关闭文件时是否同时关闭底层文件描述符
opener：自定义打开器函数

Read

读取文件：read(size=-1)
按行读取：readline(size=-1)
读取行列表：readlines(hint=-1)

Write

写入文件：write(string)
写入行列表：writelines(lines)

python 复制代码

# Read Files
file = open("file.txt")    
print(file.read())    
file.close()  
  
with open("file.txt") as file:  
    print(file.read())  
  
with open("file.txt") as file:  
    print(file.readline())
  
with open("file.txt") as file:  
    print(file.readlines())  
  
with open("file.txt") as file:    
    for line in file:    
        print(line)


# Write Files
with open("file.txt", "a") as file:  
    file.write("append")

with open("file.txt", "w") as file:
    file.write("line 1\nline 2\nline 3\n")

with open("file.txt", "w") as file:
    file.writelines(["line 1\n", "line 2\n", "line 3\n"])


# Create Files
file = open("file.txt", "x") 
file = open("file.txt", "a") 
file = open("file.txt", "w")

184. Read and Write the High Score to a File

Replit

python 复制代码

class Scoreboard(Turtle):  
    def __init__(self):  
        super().__init__()  
        self.score = 0  
        try:
            with open("data.txt") as file:
                self.high_score = int(file.read())
        except FileNotFoundError:
            self.high_score = 0 
        self.color("white")  
        self.hideturtle()  
        self.penup()  
        self.goto(0, 260)  
        self.update_scoreboard()
    
    def update_scoreboard(self):  
        self.clear()  
        self.write(f"Score: {self.score} High Score: {self.high_score}", align=ALIGNMENT, font=FONT)  
    
    def increase_score(self):  
        self.score += 1  
        self.update_scoreboard()
    
    def reset(self):  
        if self.score > self.high_score:  
            self.high_score = self.score  
            with open("data.txt", "w") as file:  
                file.write(f"{self.high_score}")  
        self.score = 0  
        self.update_scoreboard()

185. Relative and Absolute File Paths

复制代码

Root
└── Work
    ├── app.log
    └── Project
        ├── main.py
        ├── file.txt
        └── assets
            └── img.png

Absolute File Path 绝对文件路径

Root Directory 根目录：/Work/Project/file.txt

Relative File Path 相对文件路径

Parent Directory 上级目录：../app.log

Same Directory 同级目录：./file.txt

Subdirectory 下级目录：assets/img.png

186. Mail Merge Project

Replit

python 复制代码

"""
Dear [name],  
  
You are invited to my birthday this Saturday.  
  
Hope you can make it!  
  
Angela
"""

PLACEHOLDER = "[name]"  

with open("./Input/Names/invited_names.txt") as names_file:  
    names = names_file.readlines()  
  
with open("./Input/Letters/starting_letter.txt") as letter_file:  
    letter_contents = letter_file.read()  
    for name in names:  
        stripped_name = name.strip()  
        new_letter = letter_contents.replace(PLACEHOLDER, stripped_name)  
        with open(f"./Output/ReadyToSend/letter_for_{stripped_name}.txt", "w") as completed_letter:
            completed_letter.write(new_letter)