Secret Recipes of the Python Ninja

Flow restrictions

• Variables should only contain values that are only one type at each control point. In other words, when combining paths of control, for example, if...else statements, using the same variable name for two different types of values, for example, a string and an integer, must be avoided.
• All global values within a module are considered constants and can't change while the program is running.
• All control structures are allowed but for loops are restricted to built-in types and generators are heavily restricted.
• The range and xrange functions are treated equally, though xrange fields are not accessible to Python.
• Defining classes or functions at runtime is prohibited.
• While generators are supported, their scope is limited and ...