Due to the dynamic nature of class loaders, this is not possible. Class loaders are not required to tell the VM which classes it can provide, instead they are just handed requests for classes, and have to return a class or throw an exception. However, if you write your own class loaders, or examine the … Read more
Try this (see ?detach for more details): detach(“package:vegan”, unload=TRUE) It is possible to have multiple versions of a package loaded at once (for example, if you have a development version and a stable version in different libraries). To guarantee that all copies are detached, use this function. detach_package <- function(pkg, character.only = FALSE) { if(!character.only) … Read more
There’s not much of one in everyday work. However, according to the documentation for both functions (accessed by putting a ? before the function name and hitting enter), require is used inside functions, as it outputs a warning and continues if the package is not found, whereas library will throw an error.
edit: Manual installation and use of setuptools is not the standard process anymore. If you’re running Python 2.7.9+ or Python 3.4+ Congrats, you should already have pip installed. If you do not, read onward. If you’re running a Unix-like System You can usually install the package for pip through your package manager if your version … Read more
Note: Egg packaging has been superseded by Wheel packaging. Same concept as a .jar file in Java, it is a .zip file with some metadata files renamed .egg, for distributing code as bundles. Specifically: The Internal Structure of Python Eggs A “Python egg” is a logical structure embodying the release of a specific version of … Read more
1. You can’t spell The first thing to test is have you spelled the name of the package correctly? Package names are case sensitive in R. 2. You didn’t look in the right repository Next, you should check to see if the package is available. Type setRepositories() See also ?setRepositories. To see which repositories R … Read more
pip, an alternative to setuptools/easy_install, provides an “uninstall” command. Install pip according to the installation instructions: $ wget https://bootstrap.pypa.io/get-pip.py $ python get-pip.py Then you can use pip uninstall to remove packages installed with easy_install
pip install –upgrade –force-reinstall <package> When upgrading, reinstall all packages even if they are already up-to-date. pip install -I <package> pip install –ignore-installed <package> Ignore the installed packages (reinstalling instead).
Any Python file is a module, its name being the file’s base name without the .py extension. A package is a collection of Python modules: while a module is a single Python file, a package is a directory of Python modules containing an additional __init__.py file, to distinguish a package from a directory that just … Read more
To elaborate on Ignacio Vazquez-Abrams’s answer: The Python import mechanism works relative to the __name__ of the current file. When you execute a file directly, it doesn’t have its usual name, but has “__main__” as its name instead. So relative imports don’t work. You can, as Igancio suggested, execute it using the -m option. If … Read more