With a customized launcher, there are no obvious indications that the program is running on Python: icons can be customized, company and version information can be specified, and file associations behave properly.
The simpler approach is to provide a batch file or generated shortcut that directly calls the python. In this case, the application will appear to be Python and not its actual name, and users may have trouble distinguishing it from other running Python processes or file associations. With the latter approach, packages should be installed as directories alongside the Python executable to ensure they are available on the path. With the specialized launcher, packages can be located in other locations as there is an opportunity to specify the search path before launching the application.
Applications written in native code often require some form of scripting language, and the embedded Python distribution can be used for this purpose. In general, the majority of the application is in native code, and some part will either invoke python. For either case, extracting the embedded distribution to a subdirectory of the application installation is sufficient to provide a loadable Python interpreter.
As with the application use, packages can be installed to any location as there is an opportunity to specify search paths before initializing the interpreter. Otherwise, there is no fundamental differences between using the embedded distribution and a regular installation. Besides the standard CPython distribution, there are modified packages including additional functionality.
The following is a list of popular versions and their key features:. Popular scientific modules such as numpy, scipy and pandas and the conda package manager. Note that these packages may not include the latest versions of Python or other libraries, and are not maintained or supported by the core Python team. To run Python conveniently from a command prompt, you might consider changing some default environment variables in Windows.
If you regularly use multiple versions of Python, consider using the Python Launcher for Windows. Windows allows environment variables to be configured permanently at both the User level and the System level, or temporarily in a command prompt.
To temporarily set environment variables, open Command Prompt and use the set command:. These changes will apply to any further commands executed in that console, and will be inherited by any applications started from the console.
Including the variable name within percent signs will expand to the existing value, allowing you to add your new value at either the start or the end. Modifying PATH by adding the directory containing python. In this dialog, you can add or modify User and System variables. To change System variables, you need non-restricted access to your machine i. Administrator rights. Windows will concatenate User variables after System variables, which may cause unexpected results when modifying PATH.
Besides using the automatically created start menu entry for the Python interpreter, you might want to start Python in the command prompt. The installer has an option to set that up for you. This allows you to type python to run the interpreter, and pip for the package installer. Thus, you can also execute your scripts with command line options, see Command line documentation. You need to set your PATH environment variable to include the directory of your Python installation, delimited by a semicolon from other entries.
An example variable could look like this assuming the first two entries already existed :. Python uses it for the default encoding of text files e. If you have any Python 3.
The filesystem encoding see PEP for details. The Python launcher for Windows is a utility which aids in locating and executing of different Python versions.
It allows scripts or the command-line to indicate a preference for a specific Python version, and will locate and execute that version. It will prefer per-user installations over system-wide ones, and orders by language version rather than using the most recently installed version. The launcher was originally specified in PEP System-wide installations of Python 3. The launcher is compatible with all available versions of Python, so it does not matter which version is installed.
To check that the launcher is available, execute the following command in Command Prompt:. You should find that the latest version of Python you have installed is started - it can be exited as normal, and any additional command-line arguments specified will be sent directly to Python.
If you have multiple versions of Python installed e. Per-user installations of Python do not add the launcher to PATH unless the option was selected on installation. To run the global interpreter, either deactivate the virtual environment, or explicitly specify the global Python version.
You should notice the version number of your latest Python 2. Now try changing the first line to be:. Re-executing the command should now print the latest Python 3. As with the above command-line examples, you can specify a more explicit version qualifier. Assuming you have Python 2. This is for backward compatibility and for compatibility with Unix, where the command python typically refers to Python 2. The launcher should have been associated with Python files i. This means that when you double-click on one of these files from Windows explorer the launcher will be used, and therefore you can use the same facilities described above to have the script specify the version which should be used.
The key benefit of this is that a single launcher can support multiple Python versions at the same time depending on the contents of the first line. If the first line of a script file starts with! Linux and other Unix like operating systems have native support for such lines and they are commonly used on such systems to indicate how a script should be executed. This launcher allows the same facilities to be used with Python scripts on Windows and the examples above demonstrate their use.
The supported virtual commands are:. The default Python will be located and used. As many Python scripts written to work on Unix will already have this line, you should find these scripts can be used by the launcher without modification. Any of the above virtual commands can be suffixed with an explicit version either just the major version, or the major and minor version.
New in version 3. Furthermore it is possible to specify a major and architecture without minor i. The shebang lines can also specify additional options to be passed to the Python interpreter. For example, if you have a shebang line:. Then Python will be started with the -v option. The same. In some cases, a version qualifier can be included in a command to dictate which version of Python will be used by the command.
See also config. Project: recruit Author: Frank-qlu File: util. If the directory does not exist, it is created. Use the suffix provided for the base directory, and default to '. The result is just the directory '. Project: jbox Author: jpush File: util. Project: debugger Author: Vector35 File: test. Project: kobo-predict Author: awemulya File: util. Project: oss-ftp Author: aliyun File: util. Return the longest common sub-path of each pathname in the sequence paths.
Raise ValueError if paths contain both absolute and relative pathnames, the paths are on the different drives or if paths is empty.
Unlike commonprefix , this returns a valid path. Availability : Unix, Windows. Return the longest path prefix taken character-by-character that is a prefix of all paths in list. If list is empty, return the empty string ''. This function may return invalid paths because it works a character at a time. To obtain a valid path, see commonpath. Return the directory name of pathname path. This is the first element of the pair returned by passing path to the function split. Return True if path refers to an existing path or an open file descriptor.
Returns False for broken symbolic links. On some platforms, this function may return False if permission is not granted to execute os. Return True if path refers to an existing path. Returns True for broken symbolic links. Equivalent to exists on platforms lacking os. If the expansion fails or if the path does not begin with a tilde, the path is returned unchanged. Return the argument with environment variables expanded. Malformed variable names and references to non-existing variables are left unchanged.
Return the time of last access of path. The return value is a floating point number giving the number of seconds since the epoch see the time module. Raise OSError if the file does not exist or is inaccessible. Return the time of last modification of path. The return value is a number giving the number of seconds since the epoch see the time module. Return the size, in bytes, of path. Return True if path is an absolute pathname.
In this article, we will discuss how to get the current username in python. Syntax : os. Example 1: getlogin method Python3. In this function, we need to pass the Tilde operator within single quotes as an argument. Python3 importing required module import os using path. Let us see the syntax and example. Skip to content. Change Language.
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