One of programming’s little annoyances is that Microsoft Windows uses a backslash character between folder names while almost every other computer uses a forward slash: Show This is an accident of early 1980’s computer history. The first version of MS-DOS used the forward slash character for specifying command-line options. When Microsoft added support for folders in MS-DOS 2.0, the forward slash character was already taken so they used a backslash instead. Thirty-five years later, we are still stuck with this incompatibility. If you want your Python code to work on both Windows and Mac/Linux, you’ll need to deal with these kinds of platform-specific issues. Luckily, Python 3 has a new module called pathlib that makes working with files nearly painless. Let’s take a quick look at the different ways of handling filename paths and see how pathlib can make your life better! The Wrong Solution: Building File Paths by HandLet’s say you have a data folder that contains a file that you want to open in your Python program:  Windows Operating System organizes files in drive and directory. A drive is identified by a letter followed by a colon, e,g,. " Prompt> help cd7", " Prompt> help cd8" and " Prompt> help cd9". (Unix does not have the concept of drive.) Directory exhibits a tree-like structure starting from the so-called root directory, denoted by a leading back slash Displays the name of or changes the current directory. .......0. Each directory may contain sub-directories or files. Sub-directories may contains sub-sub-directories or files. The sub-directories are separated by a back slash Displays the name of or changes the current directory. .......0 (Unix uses forward slash Displays the name of or changes the current directory. .......2 as the directory separator). Directory is also called a folder or a path. An example is illustrated below: In the above example, the full-path filename for " Displays the name of or changes the current directory. .......3" is " Displays the name of or changes the current directory. .......4", which begins with the drive letter " Prompt> help cd8", followed by root directory " Displays the name of or changes the current directory. .......6", sub-directories (separated with Displays the name of or changes the current directory. .......0) and filename. The filename composes of two parts, name and extension, separated by a dot Displays the name of or changes the current directory. .......8. The file extension specifies the type of the file (e.g., " Displays the name of or changes the current directory. .......9" for text file, " D:\java\beginner>0" for Word document, " D:\java\beginner>1" for Java source file), which can be associated with a processing program. (Unix does not have the concept of file extension.) Current Drive and Current Working Directory ( D:\java\beginner>2) refer to the drive and the directory that you are currently working on. They are shown as part of the command prompt preceding " D:\java\beginner>3". For example, D:\java\beginner> In the above example, the current drive is " Prompt> help cd8", and the current working directory is " D:\java\beginner>5". To set or change the current drive, enter the drive letter followed by a colon, for examples, C:\Users\john> D: D:\> C: C:\Users\john> D: D:\> J: The system cannot find the drive specified. Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message] To set or change the current working directory, use the D:\java\beginner>6 (change directory) command. You can use " Displays the name of or changes the current directory. .......6" to refer to the root directory of the current drive, " D:\java\beginner>8" to refer to the parent directory, and " D:\java\beginner>9" to refer to the current directory. You can use absolute path which begins with the root directory (with a leading back slash), or relative path (without the leading back slash) which is relative to the current working directory. For examples, C:\Users\john> D: D:\> cd java D:\java> cd beginner D:\java\beginner> cd \java\advanced D:\java\advanced> cd .. D:\java> cd \ D:\> C: C:\Users\john> Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:] The command C:\Users\john> D: D:\> C: C:\Users\john> D: D:\> J: The system cannot find the drive specified.0 (without parameter) display the current working directory. Take note that you have to set the current drive and current working directory in two separate operations. You can use C:\Users\john> D: D:\> C: C:\Users\john> D: D:\> J: The system cannot find the drive specified.1 (directory) command to list the contents of the current working directory. For examples, D:\java\beginner> dir For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......0 The output lists all the sub-directories and files contained in the current working directory. It also contains two special entries: " D:\java\beginner>8" for the parent directory, and " D:\java\beginner>9" for the current directory. You can use special wildcard characters for filename filtering or matching. The wildcard character C:\Users\john> D: D:\> C: C:\Users\john> D: D:\> J: The system cannot find the drive specified.4 matches zero or more (any) characters. The wildcard character C:\Users\john> D: D:\> C: C:\Users\john> D: D:\> J: The system cannot find the drive specified.5 matches exactly one (any) character. For examples, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......1 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......2 Other frequently-used directory- and file-related commands include:
You could issue " Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message]2 Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message]3" to check the syntax and options of the above commands. Alternatively, you can use Windows Explorer (My Computer) to perform the above tasks, graphically. Environment and Local VariablesEnvironment variables are global system variables accessible by all the processes running under the Operating System. Environment variables are useful to store system-wide values such as the directories to search for the executable programs, the OS version, and the location of Windows binaries. (Windows registry was later created to store the ever-growing data needed for the applications in a more efficient manner.) A process could access all the environment variables, it could also maintain its own local variables, which is available to itself only. READ "". PATH Environment VariableREAD "" Miscellaneous Commands
Redirection Operators and Filtering CommandsBy default, the output of a command goes to the screen (called Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message]6), and the input of a command comes from the keyboard (called Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message]7). You can use a redirection operator to redirect input and output from/to a file or another command:
An output redirector C:\Users\john> D: D:\> cd java D:\java> cd beginner D:\java\beginner> cd \java\advanced D:\java\advanced> cd .. D:\java> cd \ D:\> C: C:\Users\john>4 involves a program and a sink (destination). An input redirector C:\Users\john> D: D:\> cd java D:\java> cd beginner D:\java\beginner> cd \java\advanced D:\java\advanced> cd .. D:\java> cd \ D:\> C: C:\Users\john>5 involves a program and a source. A pipe C:\Users\john> D: D:\> cd java D:\java> cd beginner D:\java\beginner> cd \java\advanced D:\java\advanced> cd .. D:\java> cd \ D:\> C: C:\Users\john>6 involves two programs. These filtering commands work with redirection operators for specifying the input and output:
For examples, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......3 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......4 Notes: Pipe ' C:\Users\john> D: D:\> cd java D:\java> cd beginner D:\java\beginner> cd \java\advanced D:\java\advanced> cd .. D:\java> cd \ D:\> C: C:\Users\john>3' is used to pipe into another command (or process); output redirection ' D:\java\beginner>3' is used to send the output to a file (or device such as printer) instead of Change current drive to D: Change current drive to C: Change current drive to D: Change current drive to J: [error message]6. More on Windows' File SystemPermissions[TODO] Symbolic Link (SymLink)In Windows Vista/7/8, you can create a symlink to a file or a directory (similar to Unix), via command " Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]3". Symlink could provide great convenience in many situations. You need the "Create Symbolic Link" privilege to run " Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]3" command, which only the administrators possessed by default. Start a CMD shell with administrator right ("run as administrator") to run the " Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]3" command.. Symlink is different from shortcut, which was available in the earlier Windows. CMD Shell Language and Batch FilesA batch file (also called a batch program or shell script) is a executable program that contains a sequence of commands. A batch file has a file extension of " Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]6". Batch files, which employ a legacy scripting language, possesses very simple, primitive and clumsy syntax . For examples,
The primary purpose of batch files is to automate a series of commands, instead of general programming. Use a general-purpose programming language for programming. There are also many better and more powerful scripting languages, such as Perl, Python, Java Script, Java FX Script, VB Script, among other. Batch CommandsThe frequently-used commands in the batch files are:
VariablesAll the variables belong to the type string. The names and commands are not case-sensitive. In a batch file, you can reference an environment variable using the syntax D:\java\beginner> dir9. For example, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......00. The command-line arguments can be referenced via variables For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......01 to For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......02 from right-to-left, where For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......01 is the name of the batch file. For example, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......5 The above command invoke a batch file For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......04 with command-line arguments. The command-line arguments can be referenced inside the batch file as follows: For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......05, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......06, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......07, and For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......08. To reference more argument, you need to use the command For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......09, which shifts the value of For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......10 into For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......01, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......12 into For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......10, ..., For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......02 into For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......15, and the next argument into For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......02. For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......17 and For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......18: The command For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......17 begins localization of environment changes in a batch file. That is, changes to environment variables made after For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......17 are local to this batch file. The command For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......18 restores the previous environment settings. An For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......18 is issued implicitly at the end of a batch file. Program Control ConstructsFor more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......6 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......7 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......8 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......9 Prompt> help cd0 Prompt> help cd1 Prompt> help cd2 Prompt> help cd3 The command Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]9 can be used to call another batch file or program. The control returns to the next statement following the Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]9 command, after the called program is completed (similar to calling a subroutine in programming languages). For example, suppose " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......25" is to be used in a batch file. " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......26" executes the For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......27", and returns control to the next statement. On the other hand, For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......28" alone (without Change current drive to D: Change directory to "java", relative to root "\" Change directory to "beginner", relative to "\java" Change directory to "\java\advanced" (absolute) Change directory to parent directory (relative) Change directory to root (absolute) Change current drive to C: [at the current working directory of drive C:]9) terminates the current batch file and executes the " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......25". ExamplesBelow is a sample batch file extracted from " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......31" for starting the Tomcat server. The script checks if environment variable For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......32 is defined, else set it to the current directory or the parent directory, which contains " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......33". It then packs all the command-line arguments into variable For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......34, and call " For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......35 For more information on a specific command, type HELP command-name ASSOC Displays or modifies file extension associations. ATTRIB Displays or changes file attributes. BREAK Sets or clears extended CTRL+C checking. ......34". What is an example of a file path?For example, if the file path is D:sources , the current directory is C:\Documents\ , and the last current directory on drive D: was D:\sources\ , the result is D:\sources\sources . These "drive relative" paths are a common source of program and script logic errors.
What is a file path in computer?Alternatively known as the pathname, the current path or path is the complete location or name of where a computer, file, device, or web page is located.
What is path directory?Path. A path is a slash-separated list of directory names followed by either a directory name or a file name. A directory is the same as a folder.
Does a file path include the file name?A path name can be up to 1023 characters long, including all directory names, file names, and separating slashes.
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