What is python?

Python is an open source language that is getting a lot of attention from the market.
1) Created by: Guido van Rossum nearly 11 years ago
2) Python is an interpreted, high-level programming language, pure object-oriented and powerful server-side scripting language for the Web.
3) Python is a good prototype language. In just a few minutes, you can develop prototypes that would take you several hours in other languages.

Is python the right choice for Web based Programming?

Python is another open source programming that has become popular for creating web-related applications and large programs. Scripts written in Python are often very clear to read; the language is also known for its flexibility. Whether you are looking for database tools, image manipulation scripts, or something else entirely, if it is written in Python, you will find it here.

What are uses of lambda?

It used to create small anonymous functions at run time. Like e.g.
def fun1(x):
return x**2
print fun1(2)
it gives you answer 4
the same thing can be done using
sq=lambda x: x**2
print sq(2)
it gives the answer 4

When you need ordered container of things, which will be manipulated, use lists?

Dictionary is key, value pair container and hence is not ordered. Use it when you need fast access to elements, not in ordered fashion. Lists are indexed and index of the list cannot be "string" e.g. list ['myelement'] is not a valid statement in python.

When do you use list vs. tuple vs. dictionary vs. set?

List and Tuple are both ordered containers. If you want an ordered container of constant elements use tuple as tuples are immutable objects.