Python Programming with Raspberry Pi

Reading lines

Sometimes, it is necessary to read the contents of a file by line-by-file. In Python, there are two options to do this: readline() and readlines():

• readline(): As the name suggests, this in-built function enables reading one line at a time. Let's review this using an example:

       if __name__ == "__main__":           # open text file to read          file = open('read_line.txt', 'r')           # read a line from the file          data = file.readline()           print(data)           # read another line from the file           data = file.readline()           print(data)           file.close()

When the preceding code snippet is executed (available for download as read_line_from_file.py along with this chapter), the read_line.txt file is opened and a single line is returned by the readline() function. This ...