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Variables, expressions and statements: user input

Learning objectives

  • Get the type of an object
  • Create a variable
  • Use a variable
  • Practice converting an equation to Python code
  • Find and use the operator for exponentiation
  • Practice the modulo operator
  • Practice converting a simple text question to Python code
  • Learn how to ask a user for input
  • Use input in a calculation
For teachers

Teaching goals are:

  • Learners have worked with variables
  • Learners understand the purpose of variables
  • Learners have obtained the data type of a variable
  • Learners have heard about what a data type is
  • Learners have practiced convert an equation and a text question to Python
  • Learners have read on operators
  • Learners have worked with the modulo operator
  • Learners have written code that asked for user input

Lesson plan:

Exercise 1:

  • 5 mins: prior knowledge
  • 5 mins: presentation
  • 15 mins: challenge
  • 5 mins: feedback

Exercise 2 and 3:

  • 5 mins: prior knowledge
  • 5 mins: presentation
  • 15 mins: challenge
  • 5 mins: feedback

Exercise 4:

  • 5 mins: prior knowledge
  • 5 mins: presentation
  • 15 mins: challenge
  • 5 mins: feedback

Overview

In any non-trivial calculation, we want to let our computer remember things, such as the content of a data file, or the parameters/settings we use in our program. Variables allows one to make a computer store ('remember') information. Here we use our first simple variables.

Also we practice converting an equation and a mathematical problem to Python code. We will discover the helpful modulo operator.

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      programming_language[Programming language]
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      text_files[Text files]
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    subgraph sub_programming_terms[Programming terms]
      user_input[User input]
      %% file_io[File I/O]
      %% command_line_arguments[Command-line arguments]
      variables[Variables]
      operators[Operators]
      %% functions[Functions]
      python_packages[Python packages]
      %% graphics[Graphics]
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      text_editors[Text editors]
      x_forwarding[X-forwarding]
      remote_desktop[Remote desktop]
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    python --> |is a| interpreted_language
    python --> |is a| scripting_language

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    interpreted_language --> |has a| interpreter
    scripting_language --> |is|interpreted_language
    scripting_language --> |runs| scripts
    scripts --> |are| text_files
    %% scripts --> |can use| command_line_arguments

    python --> |has| python_packages
    python --> |has| variables
    %%python --> |has| functions
    python --> |has| operators
    %%functions --> |use| variables
    operators --> |work on| variables
    %%python_packages --> |allow| graphics
    python_packages --> |allow to use| user_input
    %% python_packages --> |allow to do| file_io
    %% python_packages --> |allow to use| command_line_arguments

    uppmax --> |has| uppmax_clusters
    uppmax_clusters --> |have| uppmax_modules
    uppmax_clusters --> |have| text_editors
    uppmax_clusters --> |allow| x_forwarding
    uppmax_clusters --> |has| remote_desktop
    uppmax_modules --> |allow the use of| python_packages
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    text_editors --> |work on|text_files
    %%x_forwarding --> |allows|graphics
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    variables ~~~ uppmax

Exercises

See the exercise procedure here.

Exercise 1: input

Learning objectives

  • learn how to ask a user for input
  • use input in a calculation

Read the following section of How to Think Like a Computer Scientist: Learning with Python 3:

  • 2.10. Input

Then in section 2.14, do exercise 7.