Python comes with a built-in function that can read, write and create files. You can use it to even create text files or append any data to your chosen file. If you like, you can equally use Python to read files from one line to another.
The File Modes in Python make the program even more interesting than ever. In the remaining part of this write-up, we will teach you some very exciting things about Python and how to use it for opening a file.
How to open a file with Python
First of all, you have to use read mode.
Bear in mind that contents of Python are available in the .txt file and the file to be opened in Python will be opened in this format. The following steps can guide you through the process involved.
- First of all, open the file in the Read mode by using the code: f = open ( “filename.txt”, “r”)
- Next, you should use the mode function in that code provided above and this will help you to check if the file is available in the open mode or not. If it is available in the open mode, you can go ahead with the process. the code to use is if f .mode == ‘r’ :
- After this, you can use f.read for reading the file data and then storing it in variable content using this code: contents =f .read ()
- Afterward, you can then print the contents that you have opened.
Reading the opened text file line by line
As stated above, the files opened with Python can be opened in the .txt format. And the text file can be read line by line if the content of the file is so big that it is difficult to read all. Reading from one line to another helps a lot to prevent any form of complication. Python will help to segregate the data to be read. And present it in a mode that is very easy to read.
First of all, run the code (f1=f.readlines()) and this will help you to read the document or file in question from one line to another. Running that code will help to separate each of the lines from one to another and make the file or document available to you in a format that is readable.
If the line is readable and short, the final outcome will have a similarity to what obtains in the read mode. However, the reverse is the case if the file contains complex data; such a data is not readable and the code given above can make it readable.
Some file modes to take note of in Python
- ‘+’ mode will help to open a file for writing and reading; writing also translates to updating
- ‘r’ mode is described as the default mode and it opens the file for reading
- ‘b’ mode will help to open the file in binary mode
- ‘w' mode will open the file for writing it can also be used to create a new file if the file fails to open, probably because it does not exist. It can equally truncate the file if it exists.
- ‘x’ mode will help to create a new file. The operation will fail if the file exists already.
- ‘a’ mode will help to open the file in the append mode. It will equally create a new file if the file is not in existence.
- ‘t' mode is the default mode and will get the files opened in the text mode.
In summary, you can use the readlines functions in Python for reading the content of a document or file one after the other. You can also use the read function for reading the whole contents of the document or file. Furthermore, you can append data to any existing file by using the command open; that is, “Filename”, “a”). the function open ("filename", "w+")creates a file or document; the + commands the Python compiler to create the document or file if that file does not exist already.
Checking if a directory or file exists
Also, you can use Python to check if a directory or file is in existence or not. We can use a built-in library function to carry out this task. You can use any of the following functions to check if that directory or file is in existence or not:
- os. path.exists()
- os. path.isdir()
- os. path.isfile()
Methods for Python copy file
Python comes with several built-in functions. They can help to copy files easily using the utilities from the Operating System Shell. First of all, you should get the path that leads to the location where you saved the original file in the current directory.
Explanation of the code
First of all, we will check if the “filename.txt” file is in existence or not. If it is in existence, then we will proceed with the process. We will then store the file path in the “src” variable since the file exists. After getting the path, we will separate the file name and the path from each other. We can do this by using the split function: path.split on source variable. After executing the code it will create a print out with “file path” and a “file name” separately.
We can then create another copy of the already existing file by using Shutil Module. You can take the file named “filename.txt and add another extension to the end, “.bak” so that the new file name will look like filename.txt.bak.” The new file with .bak extension will represent the new copy or duplicate of the original file. Next, we are to use the function of the utility's copy to get a duplicate of the original destination. After running the code, you will get a duplicate file bearing the .bak extension and you can find it on the right end of the panel. Always remember that the Copy function can only copy the content of the file without copying any additional information.
More help in Python file handling here