How do I stop Ubuntu from asking for my password every time I install something?

Whenever I try to install a program I get a password authentication prompt asking me to punch in my password. I would like to know how to disable this.

I tried to google it and most of the stuff I find related to the login password, which isn't an issue for me as I disabled it at startup.

What I need to get rid of is the password prompt for installing and uninstalling stuff.

sudo nano -w /etc/sudoers

(and enter your password one last time). Then use the editor to change the line that says:

%sudo  ALL=(ALL) ALL

into:

%sudo  ALL=(ALL) NOPASSWD:ALL

or even:

%sudo  ALL=(ALL:ALL) NOPASSWD:ALL

(to allow assuming any group as well as any user).

Type sudo visudo and this screen appears:

#
# This file MUST be edited with the 'visudo' command as root.
#
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
#
# See the man page for details on how to write a sudoers file.
#
Defaults        env_reset, timestamp_timeout=120
Defaults        mail_badpass
Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:$

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification

The first command Defaults env_reset, timestamp_timeout=120 has been modified with a timeout of 120 minutes between having to enter sudo password. The normal default is 5 minutes. Although you can change this to a very large number you will still have to enter it once per boot.