Question

Assign values to variable strings named 'salutation ', ' name ', ' product', 'verbed' (past tense verb), 'room', 'animals', 'percent', 'spokesman', and 'job_title'. Print letter with these values, using letter.format().

Short answer

Define variables, create a format string, format the letter with variables, and print it.

Step-by-step solution

Define the variable strings

Assign appropriate values to the following variables: 'salutation', 'name', 'product', 'verbed', 'room', 'animals', 'percent', 'spokesman', and 'job_title'. These values should relate to any sentence or context you need them for. For example, you might set 'salutation' to "Dear", 'name' to "John", 'product' to "vacuum cleaner", and so on.

Create the format string

Write a letter that includes placeholders for each of these variables. Use curly braces `{}` as placeholders for where each variable's value will be inserted. For example, you can write: "{salutation} {name}, we are excited to introduce our new {product}. Recently, it has been {verbed} in every {room} by many {animals}." This letter should comprehensively use all the variables defined in the previous step.

Format the letter with the variable values

Use the '.format()' method to insert the values from the variables into the string placeholders. For instance, if you have the string from Step 2, you would call 'letter.format()' with all your variables inside to replace the placeholders: `formatted_letter = letter.format(salutation=salutation, name=name, product=product, verbed=verbed, room=room, animals=animals, percent=percent, spokesman=spokesman, job_title=job_title)`.

Print the formatted letter

Finally, output the completed letter with all values inserted by using the 'print' function: `print(formatted_letter)`. This will display the letter with all the variable values in their respective places.

Key concepts

Python Variables

Python variables are like containers for storing data values. When you define a variable, you write a name and assign it some value using the `=` operator. It's crucial to choose meaningful names for your variables, so their purpose is clear to anyone who reads your code. For instance, if you want to store a person's first name, you might use `first_name` as a variable name.
Python variables are not just limited to numbers—they can hold strings, lists, and other data types. For example, in the exercise provided, multiple variables are used to hold strings such as 'salutation', 'name', and 'product'. Each of these variables will contain different pieces of text that you can manipulate or display later.

• Defining a variable: `name = "Alice"`
• Updating a variable: `name = "Bob"`
• Variables can be reused throughout your code to help manage data.

This makes handling large strings or data sets much more efficient.

Format Method

The `format` method in Python is a powerful tool used for string interpolation—essentially inserting values into a string. This method enhances readability by replacing placeholders within a string with corresponding variable values. The usage of `format` is straightforward and flexible, allowing you to maintain a clean code structure.
To utilize the `format` method, you create a string with placeholders indicated by curly braces `{}`. Inside the `.format()` method, you specify the variable names that correspond to each placeholder in the string. Here's a simple example:
`string = "Hello, {}!".format('World')`, which results in `"Hello, World!"`.
When dealing with more complex strings, you can also name your placeholders, for example:
`letter = "{salutation} {name}, thank you for purchasing our {product}."`
`letter.format(salutation='Dear', name='John', product='garden hose')`.
This makes it clear exactly where each piece of data will appear in your formatted string.

String Placeholders

String placeholders are the backbone of formatting strings in Python. They are the curly braces `{}` that indicate where in a string a variable's value should be inserted. This allows you to prepare a template of your message and then fill in the dynamic parts—like names, products, or other changing information—with actual values.
Using placeholders, you can also ensure that the structure of your message remains intact, while only the content changes. This is particularly useful when generating repetitive or dynamically varying messages.

• Placeholders are defined using `{}` and can be named, like `{name}`.
• Unnamed placeholders allow for positional formatting, e.g., `"{} and {}".format("cats", "dogs")`
• Named placeholders offer keyword formatting, which is often more readable, i.e., `{animal1} and {animal2}.format(animal1="cats", animal2="dogs")`

This method keeps your strings clean and your updates simple, making your code easier to manage and understand.