Determine If Package Installed With Yum Python Api?

TLDR; I need simple a Python call given a package name (e.g., 'make') to see if it's installed; if not, install it (I can do the latter part). Problem: So there are a few code exam

Solution 1:

import yum

yb = yum.YumBase()
if yb.rpmdb.searchNevra(name='make'):
   print"installed"else:
   print"not installed"

Solution 2:

You could run 'which' on the subsystem to see if the system has the binaries you are looking for:

import osos.system("which gcc")
os.system("which obscurepackagenotgoingtobefound")

Solution 3:

For anyone who stumbles across this post later, here's what I came up with. Note that "testing" and "skip_install" are flags that I parse from the script invocation.

print"Checking for prerequisites (Apache, PHP + PHP development, autoconf, make, gcc)"
    prereqs = list("httpd", "php", "php-devel", "autoconf", "make", "gcc")

    missing_packages = set()
    for package in prereqs:
        print"Checking for {0}... ".format([package]),

        # Search the RPM database to check if the package is installed
        res = yb.rpmdb.searchNevra(name=package)
        if res:
            for pkg in res:
                print pkg, "installed!"else:
            missing_packages.add(package)
            print package, "not installed!"# Install the package if missingifnot skip_install:
                if testing:
                    print"TEST- mock install ", package
                else:
                    try:
                        yb.install(name=package)
                    except yum.Errors.InstallError, err:
                        print >> sys.stderr, "Failed during install of {0} package!".format(package)
                        print >> sys.stderr, str(err)
                        sys.exit(1)

    # Done processing all package requirements, resolve dependencies and finalize transactioniflen(missing_packages) > 0:
        if skip_install:
            # Package not installed and set to not install, so failprint >> sys.stderr, "Please install the {0} packages and try again.".format(
                ",".join(str(name) for name in missing_packages))
            sys.exit(1)
        else:
            if testing:
                print"TEST- mock resolve deps and process transaction"else:
                yb.resolveDeps()
                yb.processTransaction()

Solution 4:

importyumyb= yum.YumBase()
yb.isPackageInstalled('make')