Python 输出追加 txt
, write(), and writelines().
1. Using print()
The print() function is used to output text to the console. By default, it adds a newline character at the end of the text.
print("Hello, World!")
Output:
Hello, World!
2. Using write()
The write() method is used to write text to a file. It requires opening the file in write mode first.
file = open("output.txt", "w")
file.write("Hello, World!")
file.close()
This code snippet opens a file named output.txt in write mode, writes the text "Hello, World!" to it, and then closes the file. If the file does not exist, it will be created.
3. Using writelines()
The writelines() method is used to write a list of strings to a file. Each string will be written as a separate line.
lines = ["Line 1\n", "Line 2\n", "Line 3\n"]
file = open("output.txt", "w")
file.writelines(lines)
file.close()
This code snippet opens a file named output.txt in write mode, writes the list of strings lines to it, and then closes the file. Each string will be written as a separate line.
Appending text to a TXT file
To append text to an existing TXT file, we need to open the file in append mode by passing the "a" argument to the open() function.
file = open("output.txt", "a")
file.write("This is appended text.")
file.close()
This code snippet opens the file output.txt in append mode, writes the text "This is appended text." to it, and then closes the file. If the file does not exist, it will be created.
Journey Diagram
Now, let's create a journey diagram using Mermaid to visualize the process of outputting and appending text to a TXT file in Python.
journey
title Output and Append Text to TXT File in Python
section Output Text
Python code
Python->>TXT File: Using write()
TXT File-->>Python: File closed
section Append Text
Python code
Python->>TXT File: Using append mode
TXT File-->>Python: File closed
The journey diagram above illustrates the two steps involved in outputting and appending text to a TXT file in Python. The first step is to output text using the write() method, and the second step is to append text using the append mode.
Class Diagram
Finally, let's create a class diagram using Mermaid to represent the classes and their relationships in the process of outputting and appending text to a TXT file in Python.
classDiagram
class Python {
- write()
}
class TXTFile {
- open()
- close()
- write()
}
Python --> TXTFile
The class diagram above represents the two classes involved in the process: Python and TXTFile. The Python class has a method write(), and the TXTFile class has three methods: open(), close(), and write(). The arrow between the classes represents the relationship between them.
In conclusion, Python provides convenient methods for outputting and appending text to a TXT file. We can use the print() function to output text to the console, the write() method to write text to a file, and the writelines() method to write a list of strings to a file. To append text to an existing file, we can open it in append mode using the "a" argument. Additionally, we can use Mermaid to create journey and class diagrams to visualize the process and relationships between different entities.
Now that you have learned how to output and append text to a TXT file in Python, and how to use Mermaid to create diagrams, you can apply this knowledge to your own projects and enhance your understanding of these concepts. Happy coding!
