Backup all installed (third-party) .apk files from your Android phone to your computer. No root required.

backupApks.py

"""
backupApks.py

Backup all installed (third-party) .apk files from your Android phone to your computer.
Requires adb/adb.exe in %path%. No root required.
You can download adb from here: https://developer.android.com/studio/releases/platform-tools.html
You should try to keep the phone screen on while downloading the apks, otherwise transfer speed might drop drastically.
"""

import os
import subprocess

outputDir = 'apks/'
tempfile = os.path.join(outputDir, '0temp.apk')

if not os.path.isdir(outputDir):
    os.makedirs(outputDir)

packages = subprocess.run('adb shell pm list packages -3'.split(), stdout=subprocess.PIPE, shell=True)
packages = packages.stdout.decode('utf8').strip().split('\n')

errors = []
skipped = []
for line in packages:
    package = line[8:].strip()
    print(package)

    cmd = 'adb shell pm path'.split()
    cmd.append(package)
    filenames = subprocess.run(cmd, stdout=subprocess.PIPE, shell=True).stdout.decode('utf8').strip().split('\n')

    if len(filenames) > 0:
        for file in filenames:
            filepath = file[8:].strip()

            filename = os.path.basename(filepath)

            if filename == "base.apk" and len(filenames) == 1:
                filename ='%s.apk' % package
            else:
                filename ='%s.%s' % (package, filename)

            if os.path.isfile(os.path.join(outputDir, filename)):
                print("Skipping: %s already exists" % filename)
                skipped.append(filename)
                continue

            cmd = 'adb pull'.split()
            cmd.append(filepath)
            cmd.append(tempfile)
            print("Press Ctrl-C to abort")
            print(' '.join(cmd))
            try:
                with subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) as p:
                   for line in p.stdout:
                        print(line.decode('utf8').strip(), end='\r')
                os.rename(tempfile, os.path.join(outputDir, filename))
            except KeyboardInterrupt:
                print("Aborted %s" % package)
                errors.append(package)
            print('\n')

print("")
if skipped:
    print("Following packages were skipped:")
    for ski in skipped:
        print(ski)
print("")
if errors:
    print("Following packages were aborted:")
    for err in errors:
        print(err)
else:
    print("No errors")