1 Python FILE HANDLING
1. What is File Handling?
File handling means working with files using Python.
In simple words:
👉 Python can create files
👉 Python can read files
👉 Python can write data to files
👉 Python can delete files
Files help us save data permanently.
2. Types of Files
Common file types:
-
Text files →
.txt -
CSV files →
.csv -
JSON files →
.json
In this chapter, we use text files.
3. Open a File
Python uses the open() function.
Syntax
File Modes
| Mode | Meaning |
|---|---|
"r" |
Read |
"w" |
Write (overwrite) |
"a" |
Append |
"x" |
Create new file |
4. Read a File ("r")
Example
5. Read File Line by Line
Example
6. Write to a File ("w")
⚠️ This will overwrite the file.
Example
7. Append to a File ("a")
Adds text without deleting old data.
Example
8. Best Way: Using with Statement
|
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with automatically closes the file. |
Example (Read)
Example (Write)
9. Read Only One Line
Example
10. Read All Lines as List
Example
11. Check if File Exists
Example
12. Delete a File
Example
13. Common Beginner Mistakes
❌ Forgetting to Close File
❌ File not closed.
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✔ Use with. |
❌ Writing in Read Mode
❌ Error.
14. Simple Practice Examples
Example 1: Save User Name
Example 2: Read Saved Name
Example 3: Append Data
15. Summary (Python File Handling)
|
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✔ Files store data permanently ✔ Use open() to work with files ✔ "r", "w", "a" modes are important ✔ with is the best practice ✔ Very useful in real applications |
📘 Perfect for Beginner eBook
This chapter is ideal for:
-
Python beginner books
-
School & college students
-
Self-learners
If you want next, I can write:
-
File Handling Exercises
-
CSV File Handling
-
JSON File Handling
-
Mini Python Projects
Just tell me 😊
