Python read files in windows

They are used to permanently store data in a non-volatile memory e. Since Random Access Memory RAM is volatile which loses its data when the computer is turned off , we use files for future use of the data by permanently storing them.

When we want to read from or write to a file, we need to open it first. When we are done, it needs to be closed so that the resources that are tied with the file are freed. Python has a built-in open function to open a file. This function returns a file object, also called a handle, as it is used to read or modify the file accordingly. We can specify the mode while opening a file.

In mode, we specify whether we want to read r , write w or append a to the file. We can also specify if we want to open the file in text mode or binary mode. On the other hand, binary mode returns bytes and this is the mode to be used when dealing with non-text files like images or executable files. Unlike other languages, the character a does not imply the number 97 until it is encoded using ASCII or other equivalent encodings.

Moreover, the default encoding is platform dependent. In windows, it is cp but utf-8 in Linux. So, we must not also rely on the default encoding or else our code will behave differently in different platforms. Hence, when working with files in text mode, it is highly recommended to specify the encoding type. Closing a file will free up the resources that were tied with the file.

It is done using the close method available in Python. Python has a garbage collector to clean up unreferenced objects but we must not rely on it to close the file.

This method is not entirely safe. If an exception occurs when we are performing some operation with the file, the code exits without closing the file. A safer way is to use a try This way, we are guaranteeing that the file is properly closed even if an exception is raised that causes program flow to stop.

The best way to close a file is by using the with statement. This ensures that the file is closed when the block inside the with statement is exited. Check out my profile. In this Python tutorial , we will learn how to read a binary file in python , and also we will cover these topics: How to read a binary file to an array in Python How to read a binary file into a byte array in Python How to read a binary file line by line in Python Python read a binary file to Ascii How to read a binary file into a NumPy array in Python How to read a binary file into CSV in Python Table of Contents show.

Python read a binary file. Python read a binary file to an array. Python read a binary file into a byte array. Python read a binary file line by line. A string in python is surrounded by either single quotation marks, or double quotation marks. But since files are not always conveniently inside the same folder as your code, you can also have the full path of the file stored in this string.

This is always better. Note that the slash in the path is a forward slash, unlike the backslash windows often uses. Using backslashes will not work here. If you still want to use backlashes, you will have to replace a single backslash with a double one as follows:.

This is because the backslash is a reserved character or an illegal character in Python. Other useful escape characters can be found here. We will learn smarter ways to get the path more easily by browsing files in the file explorer window, in the following lessons. As long as you have a file with the column like data shown previously in it, you will immediately get a table as the output which for the type of data I showed above, would look like this:.

If this shows alright it means that your data file reading was successful. There are certain problems with the header, we will fix that later. Another great way of checking if your data was read in the columns separated appropriately, you can use the head function to display just a quick preview of the data as follows. This line of code should be good enough to read all tab separated, space separated, or other delimiter separated files.

This will show you the data where the header names of the columns are simply 0 and 1. This is what we want. To obtain the raw 2D array, out of this pandas data object, you can use the value function on the object like this:.

Pandas does a great job of reading large files fast. I use it mostly just for that. From here onward, I find it easier to do all of the data processing on the raw 2D arrays.

This tells Python to fetch all rows : from the 0th column. To get the second column you would use [:,1]. It is important to remeber that indexing always starts from 0 in Python. The output for this gives me the individual arrays to be plotted, or do analysis on. The output should now look as follows:. One of the easiest libraries to work with while plotting data in Python is matplotlib. It is highly customization and can do wonders within a few lines of code.

Refer to the below attached screenshot. Output Explanation: Now, as expected the output is 5, which is the total number of rows our sheet has, and this includes the header row. So, moving on to the next example, we will demonstrate the working of python code, which will read an excel file and print the total number of columns the excel sheet has. Then we have our final print statement, which will print the number of columns our excel sheet has and it will be done by the ncols.

The ncols can be seen as the number of columns and are used to find out the number of columns any excel spreadsheet has.

Refer the below-attached screenshot for output:. Output Explanation: The output is 3, meaning out the excel sheet has a total of three columns. Until now, we demonstrated with columns and rows for trying out excel operations, for our next example, we will attempt to read data from a whole column. The code for reading the column is as below:.

Code Explanation: Without any changes in our initial part of code, we have file pat, then our workbook and excel sheet. Then we our values by the cell. Our loop will check for every single cell. They will work in a way that will print out the data values from the first column of every row, meaning the whole of the first column.