This can be efficient when you subsequently process the data but it require large amounts of memory to hold the entire file. Other approaches to reading files will typically expect to read the whole file in one go.

The larger the file the more the processing time required. This is because we only process one record at a time so the memory requirements of the programs will be very small. The file we will be using is only a small file (131 data records), but the approach we are using will work for any size of file. We will split the file into smaller files based on some processing.We will perform simple processing of the file data and print the output.We will read the file one line at a time ( line = record = row of a table).We will use standard core Python functions to do this.There are in fact many different approaches to reading data files and which one you choose will depend on such things as the size of the file and the data format of the file. In this episode we will look at how to read and write files of data in Python. Additionally, apart from when you are developing, most of your program output will be written to a file. The reality is that most of the data that your program uses will be read from a file. Python has an input() function which will ask for input from the user, but for any large amounts of data this will be an impractical way of collecting data. In all of our examples so far, we have directly allocated values to variables in the code we have written before using the variables. Use with open() as to open files for reading and auto-close filesĬreate and open for writing or appending and auto-close files

Python create and write to file