Desktop implementation is platform-dependent, so it is necessary to check the operating system supports Desktop or not. The Desktop class looks for an associated application registered on the native desktop to handle a file. If there is no associated application or application is fails to be launched, it throws the FileNotFoundException. Launches the user default browser to show a specified URI.
The open method of Desktop class launches the associated application to open a file. It takes a file as an argument. The signature of the method is:. When we run the above program, it opens the specified text file in the default text editor.
We can also open the. Java FileInputStream class is used to open and read a file. We can open and read a file by using the constructor of the FileInputStream class.
The signature of the constructor is:. It accepts a file as an argument. It throws FileNotFoundException if the file does not exist or file name is a directory. Java BufferedReader class reads text from a character input stream. We use the constructor of the BufferedReader class to open or read a file. It creates a buffering character-input stream that uses a default?
It uses a default size input buffer. Java FileReader class is also used for opening and reading a file. It is a convenience for reading characters of the files. It is used for reading raw bytes using the FileInputStream class. We use the constructor of the FileInputStream class to open and read a file. It throws the FileNotFoundException if the specified file does not exist or the file name is a directory.
Java Scanner class is also used for opening and reading a file. The Scanner class belongs to java. The constructor of Scanner class is used for opening and reading a file. It accepts a file to be scanned as an argument. It also throws FileNotFoundException , if the source of the file is not found.
Next, type the file name along with its extension and press Enter. To open the file in Command Prompt with a specific program , use the below command. You can just type it as following:. Open the PowerShell window. You can do that on Windows by searching for it in the Start menu. Use the below command to go to the folder where the file you want to open is located. Once you are in the folder, execute the below command to open the file with PowerShell.
Replace the dummy file name with the actual file name and its extension. As long as there is a compatible program, the file will be opened. The function takes two arguments or parameters: one that accepts the file's name and another that saves the access mode. It returns a file object and has the following syntax:.
If the file isn't in the same directory, you must mention the file's full path when writing the file name parameter. For instance, to open an "example. Python has several access modes, and these modes govern the operations that you can perform on an open file. In other words, every access mode refers to how the file can be used when it's open differently. Access modes in Python also specify the position of the file handle. You can think of the file handle as a cursor indicating from where the data must be read or written.
That said, using the access mode parameter is optional, as seen in the previous examples. There are two other parameters you can use to specify the mode you want to open the file in. Python reads files in text mode by default, which is specified with the parameter "t. In contrast, using the binary mode "b" when using the open function returns bytes. Binary mode is typically used when handling non-text files such as images and executables. Here are few examples of using these access modes in Python:.
Besides having a cleaner syntax, the "with" statement also makes exception handling easier when working with file objects. It is considered best practice to use the with statement when working with files whenever applicable. A significant advantage that using the with statement offers is that it automatically closes any files you've opened after the operation is complete.
Thus, you don't have to worry about closing the file and cleaning up after performing any operation on a file. To read a file using the with statement, you would write the following lines of code:. When the second line of code runs, all of the data stored in "example. If you wanted to write data to the same file, you would run the following code:. Reading a file in Python is straightforward — you must use the 'r' parameter or not mention a parameter at all since it is the default access mode.
That said, there are other ways to read data from a file in Python. For example, you could use the read size method built into Python to read the specified size of data. If you do not specify the size parameter, the method will read the file until its end.
Let's assume that "example. This file has two lines. To read the file using the read method, you would use the following code:. In the example above, the read method returns the new line character when the line ends.
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