WP 4.3.1 new install on localhost missing php.ini [closed]

As you discovered php.ini is not part of WordPress but rather a file that exists in your local environment.

Once you track down the correct php.ini file and make the change to the upload_max_filesize parameter you may need to restart your local Apache instance.

That being said though, I’m not sure the file you mentioned is the correct file since it has the .default extension.

Are you running the native LAMP stack that comes on Yosemite or did you use a third-party tool to get your local environment up and running? Examples of third-party installers include MacPorts, Homebrew, XAMPP, MAMP, manual installs.

Each one is a little different so knowing that bit of info will help you track down the location of your INI file.