File handling

File I/O (input and output) is essential in a number of scenarios. For example:

• Working with measured or scanned data. Measurements are stored in files that need to be read to be analyzed.
• Interacting with other programs. Save results to files so that they can be imported in other applications, and vice-versa.
• Storing information for future reference or comparisons.
• Sharing data and results with others, possibly on other platforms using other software.

In this section, we will cover how to handle file I/O in Python.

Interacting with files

In Python, an object of type file represents the contents of a physical file stored on disk. A new file object may be created using the following syntax:

myfile = open('measurement.dat','r') # creating a new file object from an existing file

The contents of the file may be accessed, for instance, with this:

print(myfile.read())

Usage of file objects requires some care. The problem is that a file has to be closed before it can be...