Heat tape is ultimately cheaper and has a larger surface area. Most people shy away from heat cable for a variety of reasons (some reasonable/true, some not) but generally it’s more expensive and there’s a risk of small hot spots depending on the installation.
Either solution needs a thermostat especially with ball pythons. Ask them to cycle it for you and/or explain the heat cable choice. They shouldn’t have a problem with it and you can bring a little IR temp gun to verify.