Python Read Files and parameters: Essential python tutorials 24 | Better4Code
Python Read Files and Parameters: Python is a versatile programming language that allows users to read and manipulate files of various formats. Whether you are working with text files, CSV files, or binary files, Python provides numerous functions and modules to help you access and extract data from them. In this article, we will explore the various parameters associated with reading files in Python and provide examples of how to use them.
Opening a File
Before we can read a file in Python, we need to open it using the built-in open() function. The syntax for opening a file is as follows:
file_object = open("filename", "mode")
Here, filename is the name of the file we want to open, and mode specifies how we want to open it. The mode parameter can take several values, including:
- “r”: read-only mode (default)
- “w”: write mode, truncating the file if it exists
- “x”: exclusive creation mode, failing if the file already exists
- “a”: append mode, writing to the end of the file if it exists
- “b”: binary mode, for non-text files
- “t”: text mode, for text files (default)
For example, to open a file called “example.txt” in read-only mode, we would use the following code:
file_object = open("example.txt", "r")
Reading a File
Once we have opened a file, we can read its contents using the read() method. The read() method returns the entire contents of the file as a string.
file_object = open("example.txt", "r")
file_contents = file_object.read()
print(file_contents)
Alternatively, we can read a file line by line using the readline() method. The readline() method reads one line at a time and returns a string.
file_object = open("example.txt", "r")
line1 = file_object.readline()
line2 = file_object.readline()
print(line1)
print(line2)
Finally, we can read all the lines in a file at once and store them in a list using the readlines() method. The readlines() method returns a list of strings, where each string represents a line in the file.
file_object = open("example.txt", "r")
lines = file_object.readlines()
print(lines)
Closing a File
After we have finished reading a file, we should close it using the close() method to free up system resources.
file_object = open("example.txt", "r")
file_contents = file_object.read()
file_object.close()
