Create a file called myfile.txt, add some names, one for each line, and save it in the same place as the python program.

Alice
Bob
Carl

You can use the function open to open the file and return a file value. This code opens the file for reading and assigns the value to the myfile variable.

myfile = open('names.txt', 'r')
# do something with the file here
myfile.close()

The open function has two parameters, the first is the name of the file 'names.txt'. The second parameter is the type of operation we want to perform on the file. In this example, we use 'r' which means we want to read the file.

The myfile variable represents a file, and as such, you can call functions that are specific to files. The function only works on files, so it is called using the file variable with the . character followeed by the function name.

When we are finished working with the file, we must always remember to close the file.

Once we open the file we can read from it. The following code opens a file, then uses the read() function to read all the data in a file.

myfile = open('names.txt', 'r')

lines = myfile.read()

print(lines)

myfile.close()

Another function is readline(), which reads a file, line by line. This is useful for large files.

In the following example, once we open the file, we then use a loop to read the file one line at a time until there are no more lines.

myfile = open('names.txt', 'r')

has_more_lines = True
while has_more_lines:
  line = myfile.readline()
  if not line:
    has_more_lines = False
  else:
    print(line)

myfile.close()