In Python, file manipulation is a very important part. Among them, the seek function is a commonly used file manipulation function, which allows us to move the position of the read and write pointer in the file.
This article will provide a comprehensive and in-depth introduction to the use of seek functions in Python, including its basic concepts, common usage, and advanced skills. Autumn and Winter Check-in Challenge
Basic usage. Define the file object.
Before we can use the seek function, we need to open a file and create a file object. For example:
file = open("example.txt", "r")
Use the seek function to move the read/write pointer.
We can use the two arguments of the seek function to specify the number of bytes to move and the starting position. The start position can be 0 (starting from the beginning of the file (meaning starting from the current location) or 2 (starting from the end of the file). For example:
Move the read and write pointer to the 10th byte position of the fileseek(10)
Read or write data.
After moving the read-write pointer, we can use the read() or write() function to read or write the data. For example:
Read 5 bytes of data from the current location data = fileread(5)print(data) output: hello
Write data to the back of the current location.
file.write("world")
Advanced techniques. Skip read data.
When we use the read() function to read data, the read-write pointer automatically moves forward. If we want to skip the data that has already been read, we can use the seek() function to move the read/write pointer back to its original position. For example:
Read the first 10 bytes of data data = fileread(10)print(data) output: example skips the read data and relocates the read and write pointer to the beginning of the fileseek(0)
File pointer reset.
When we write data to a file, the original data may be overwritten. In order to recover the original data, we can use the seek() function to move the read/write pointer to its original position. For example:
Write data to the file"hello"file.write("hello"Reset the read/write pointer to the beginning of the file to restore the original data fileseek(0) #
Summary. The seek function is a very useful function for manipulating files in Python. It allows us to move the position of the read and write pointer in the file, enabling a variety of complex file operations.
In practice, we should use the seek function according to specific needs to achieve efficient file reading and writing operations.