Skip to main content

Python Reading from and writing to files

Reading from and writing to files in Python is straightforward and can be accomplished using the built-in open() function. Here's a basic guide to help you get started:

Reading from a File

  1. Open the File: Use open() to open the file. You can specify the mode as 'r' for reading.
  2. Read the File: Use methods like read(), readline(), or readlines() to read the file contents.
  3. Close the File: Always close the file using close() to free up system resources.
Here's an example of reading the entire content of a file:

# Open the file in read mode
with open('example.txt', 'r') as file:
    # Read the contents of the file
    contents = file.read()

# Print the contents
print(contents)


Writing to a File

  1. Open the File: Use open() with mode 'w' for writing, 'a' for appending, or 'w+' for reading and writing.
  2. Write to the File: Use methods like write() or writelines() to write data to the file.
  3. Close the File: Close the file using close().

Here's an example of writing to a file:

# Open the file in write mode with open('example.txt', 'w') as file: # Write some text to the file file.write('Hello, world!') # If you want to append to the file, use 'a' mode with open('example.txt', 'a') as file: # Append some text to the file file.write('\nAppended text.')


Using with Statement

Using the with statement is a good practice as it automatically closes the file for you, even if an exception occurs.

Full Example: Reading and Writing

Here’s a full example demonstrating both reading from and writing to a file:

# Write to the file with open('example.txt', 'w') as file: file.write('Hello, world!\n') file.write('This is a test file.\n') # Read from the file with open('example.txt', 'r') as file: contents = file.read() print(contents)


Common File Modes

  • 'r': Read (default mode). Opens the file for reading.
  • 'w': Write. Opens the file for writing (creates a new file or truncates the existing file).
  • 'a': Append. Opens the file for appending (creates a new file if it doesn't exist).
  • 'r+': Read and write. Opens the file for both reading and writing.
  • 'w+': Write and read. Opens the file for writing and reading (creates a new file or truncates the existing file).
  • 'a+': Append and read. Opens the file for appending and reading (creates a new file if it doesn't exist).

By using these simple techniques, you can easily read from and write to files in Python.

Comments

Post a Comment

Popular posts from this blog

TechUplift: Elevating Your Expertise in Every Click

  Unlock the potential of data with SQL Fundamental: Master querying, managing, and manipulating databases effortlessly. Empower your database mastery with PL/SQL: Unleash the full potential of Oracle databases through advanced programming and optimization. Unlock the Potential of Programming for Innovation and Efficiency.  Transform raw data into actionable insights effortlessly. Empower Your Data Strategy with Power Dataware: Unleash the Potential of Data for Strategic Insights and Decision Making.
Post a Comment
Read more

Relationships between tables

In Power BI, relationships between tables are essential for creating accurate and insightful reports. These relationships define how data from different tables interact with each other when performing analyses or creating visualizations. Here's a detailed overview of how relationships between tables work in Power BI: Types of Relationships: One-to-one (1:1):   This is the most common type of relationship in Power BI. It signifies that one record in a table can have multiple related records in another table. For example, each customer can have multiple orders. Many-to-One (N:1):   This relationship type is essentially the reverse of a one-to-many relationship. Many records in one table can correspond to one record in another table. For instance, multiple orders belong to one customer. One-to-Many (1:N):   Power BI doesn't support direct one-to-many relationships.  One record in table can correspond to many records in another table.  Many-to-Many (N:N):  ...
Post a Comment
Read more

SQL Fundamentals

SQL, or Structured Query Language, is the go-to language for managing relational databases. It allows users to interact with databases to retrieve, manipulate, and control data efficiently. SQL provides a standardized way to define database structures, perform data operations, and ensure data integrity. From querying data to managing access and transactions, SQL is a fundamental tool for anyone working with databases. 1. Basics of SQL Introduction : SQL (Structured Query Language) is used for managing and manipulating relational databases. SQL Syntax : Basic structure of SQL statements (e.g., SELECT, INSERT, UPDATE, DELETE). Data Types : Different types of data that can be stored (e.g., INTEGER, VARCHAR, DATE). 2. SQL Commands DDL (Data Definition Language) : CREATE TABLE : Define new tables. ALTER TABLE : Modify existing tables. DROP TABLE : Delete tables. DML (Data Manipulation Language) : INSERT : Add new records. UPDATE : Modify existing records. DELETE : Remove records. DQL (Da...
Post a Comment
Read more