Variables & Data Types

What this module covers

By the end of it

• Describe Python's memory model: names are labels bound to objects, not boxes holding values
• Use id(), is, and == correctly, and explain precisely when they disagree
• Explain dynamic typing and its trade-offs against static typing
• Work confidently with Python's core types: int, float, bool, str, None, complex
• Convert between types safely, and predict when a conversion raises versus silently truncates
• Apply the truthiness rules, including the traps (bool("0"), bool([]), bool(0.0))
• Explain floating-point imprecision and choose decimal when money is involved
• Distinguish mutable from immutable types and predict the consequences