E ExamMaster

Engineering Python · Functions & Files

Modules and import

In Engineering Python because labs lean on the standard library — import math or json is how you reuse battle-tested code.

`import` loads a module. Dot access reaches its functions and constants. You will meet `math` and `json` constantly before NumPy and pandas.

  • Engineering Python
  • Easy level
  • 4 concepts

1import and dotted names

`import math` loads the math module. `math.sqrt(9)` calls a function defined there.

Figure. import math loads the math module. math.sqrt(9) calls a function defined there and prints 3.0.

import math

import math
print(math.sqrt(9))
What does `import math` do?
  1. Loads the math module so you can use math.name
  2. Prints every math function
  3. Creates a file called math.py always

import loads a module into the session.

2from ... import

`from math import sqrt` binds `sqrt` directly. Use sparingly so readers still know where a name came from.

Figure. from math import sqrt binds sqrt directly. Use sparingly so readers still know where a name came from — math.sqrt keeps the module in the name.

Takeaway

  1. Idea`from math import sqrt` binds `sqrt` directly. Use sparingly so readers still know where a name came from.

3json for structured text

`json.loads` parses a JSON string into Python lists/dicts; `json.dumps` goes the other way. Labs often exchange small tables as JSON text.

Figure. json.loads parses a JSON string into Python lists/dicts; json.dumps goes the other way. loads('{"n": 3}') then data["n"] is 3.

Takeaway

  1. Idea`json.loads` parses a JSON string into Python lists/dicts; `json.dumps` goes the other way. Labs often exchange small tables as JSON text.

json.loads

import json
data = json.loads('{"n": 3}')
print(data["n"])

4Lab: import math

Import math and print a sqrt the check can see.

Figure. Import math and print math.sqrt(16). The dotted call yields 4.0 — the value the check can see.

Takeaway

  1. IdeaImport math and print a sqrt the check can see.

Coding lab. Use math.sqrt runs in the app, with checks on your output.

Notes

  • In Engineering Python because labs lean on the standard library — import math or json is how you reuse battle-tested code.
  • `import math` loads the math module. `math.sqrt(9)` calls a function defined there.
  • `from math import sqrt` binds `sqrt` directly. Use sparingly so readers still know where a name came from.

Exam traps & shortcuts

  • Run one cell at a time and read stdout before changing more lines.
  • Names are labels for values; rebinding a name does not rewrite old prints.

Recap

import loads a module; dotted names call into it; json moves structured text.

import and dotted names
`import math` loads the math module. `math.sqrt(9)` calls a function defined there.
from ... import
`from math import sqrt` binds `sqrt` directly. Use sparingly so readers still know where a name came from.
json for structured text
`json.loads` parses a JSON string into Python lists/dicts; `json.dumps` goes the other way. Labs often exchange small tables as JSON text.
Lab: import math
Import math and print a sqrt the check can see.

Practise Modules and import

Reading is free and needs no account. Practice, mocks and progress live in the app.

  • A 2-question practice set that ends the chapter
  • 1 quick check with worked explanations
  • Timed mocks scored with the real marking scheme
  • Readiness tracked per topic, kept on your device
Continue with Google — freeNo card, no trial. Works offline once installed.