Render_template function in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the function that renders HTML templates in Flask.

Flask

from flask import [1]

Drag options to blanks, or click blank then click option'

Arender_template

Brequest

CFlask

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'Flask' instead of 'render_template'.

Using 'request' which is for handling data, not templates.

The render_template function is imported from Flask to render HTML files.

2fill in blank

medium

Complete the code to return the 'index.html' template from a Flask route.

Flask

@app.route('/')
def home():
    return [1]('index.html')

Drag options to blanks, or click blank then click option'

Aredirect

Burl_for

Crequest

Drender_template

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'redirect' which sends users to another URL.

Using 'request' which handles incoming data.

Use render_template to show the 'index.html' page when the home route is accessed.

3fill in blank

hard

Fix the error in the code to correctly render 'about.html' with Flask.

Flask

@app.route('/about')
def about():
    return render_template([1])

Drag options to blanks, or click blank then click option'

A"about.html"

Babout.html

C'about.html'

Dabout

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the template name without quotes causes a NameError.

Using just the word 'about' without '.html' is incorrect.

The template name must be a string with quotes. Both "about.html" (A) and 'about.html' (C) are correct.

4fill in blank

hard

Fill both blanks to pass a variable 'name' with value 'Alice' to the template.

Flask

return render_template('hello.html', [1]=[2])

Drag options to blanks, or click blank then click option'

Aname

B'Alice'

CAlice

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the string value 'Alice'.

Using a different variable name than 'name'.

Pass the variable name as name and its value as the string 'Alice' to the template.

5fill in blank

hard

Fill all three blanks to render 'profile.html' passing the 'username' variable with value 'john_doe'.

Flask

return render_template('[1]', [2]=[3])

Drag options to blanks, or click blank then click option'

Aprofile.html

Busername

C'john_doe'

Dage

E30

Attempts:

3 left

💡 Hint

Common Mistakes

Passing variables without quotes for string values.

Mixing variable names or values.

Render 'profile.html' passing the variable username with value 'john_doe' to the template.

Practice

1. What is the main purpose of the render_template function in Flask?

easy

A. To connect Python code with HTML pages and send data to them

B. To start the Flask web server

C. To handle database connections

D. To create new HTML files automatically

Solution

1. Step 1: Understand what render_template does

   The render_template function is used to link Python code with HTML templates so that dynamic content can be shown on web pages.

2. Step 2: Compare options with this purpose

   Only To connect Python code with HTML pages and send data to them correctly describes this purpose. Options A, B, and C describe unrelated tasks.

3. Final Answer:

   To connect Python code with HTML pages and send data to them -> Option A

4. Quick Check:

   render_template connects Python and HTML [OK]

Hint: Remember: render_template links Python to HTML pages [OK]

Common Mistakes:

• Thinking render_template starts the server
• Confusing render_template with database functions
• Assuming it creates HTML files automatically

2. Which of the following is the correct way to use render_template to show the file home.html?

easy

A. render_template('home.html')

B. render_template(home.html)

C. return render_template(home.html)

D. return render_template('home.html')

Solution

1. Step 1: Check the syntax for render_template

   The function requires the template filename as a string inside quotes and must be returned from the route function.

2. Step 2: Identify the correct option

   return render_template('home.html') correctly uses quotes around the filename and returns the result. Options A and D miss the return statement, and return render_template(home.html) misses quotes around the filename.

3. Final Answer:

   return render_template('home.html') -> Option D

4. Quick Check:

   Use quotes and return the render_template call [OK]

Hint: Always return render_template with filename as a string [OK]

Common Mistakes:

• Forgetting to return the render_template call
• Not putting the filename in quotes
• Calling render_template without return

3. Given this Flask route code:

from flask import Flask, render_template
app = Flask(__name__)

@app.route('/')
def home():
    user = 'Alice'
    return render_template('welcome.html', username=user)

What will the template receive as the variable username?

medium

A. 'Alice'

B. 'user'

C. null

D. An error occurs

Solution

1. Step 1: Understand variable passing in render_template

   The function passes variables as keyword arguments. Here, username=user sends the value of user which is 'Alice'.

2. Step 2: Identify the value received in the template

   The template variable username will have the string 'Alice'. 'Alice' matches this. 'user' is the variable name as string, which is incorrect. null and D are wrong because no error occurs and the value is not null.

3. Final Answer:

   'Alice' -> Option A

4. Quick Check:

   Variable value passed, not variable name [OK]

Hint: render_template passes variable values, not names [OK]

Common Mistakes:

• Passing variable name as string instead of value
• Assuming template gets null if variable not defined
• Expecting an error without syntax issues

4. What is wrong with this Flask route code?

from flask import Flask, render_template
app = Flask(__name__)

@app.route('/')
def index():
    return render_template('index.html', title=Welcome)

medium

A. The template filename should be in double quotes

B. Missing return statement before render_template

C. The variable value Welcome is not in quotes, causing a syntax error

D. render_template cannot accept variables

Solution

1. Step 1: Check the variable argument syntax

   The value passed to title is Welcome without quotes, which Python treats as a name, causing a syntax error.

2. Step 2: Identify the correct fix

   Putting quotes around Welcome (like 'Welcome' or "Welcome") fixes the error. Options A, B, and D are incorrect because quotes can be single or double, return is present, and render_template accepts variables.

3. Final Answer:

   The variable value Welcome is not in quotes, causing a syntax error -> Option C

4. Quick Check:

   String values must be quoted in render_template [OK]

Hint: Put quotes around string values passed to render_template [OK]

Common Mistakes:

• Forgetting quotes around string values
• Thinking return is missing
• Believing render_template can't take variables

5. You want to show a list of products on a webpage using Flask. Which code correctly passes the list products = ['apple', 'banana', 'cherry'] to the template products.html so it can display them?

hard

A. return render_template('products.html', products='products')

B. return render_template('products.html', products=products)

C. return render_template('products.html', items=products)

D. render_template('products.html', products=products)"

Solution

1. Step 1: Understand variable passing to templates

   The variable name used in the template should match the keyword argument name in render_template. Passing the actual list variable as the value is required.

2. Step 2: Identify correct usage

   return render_template('products.html', products=products) passes the list products correctly with the same name. return render_template('products.html', items=products) uses a different name items, which is valid but may confuse if template expects products. return render_template('products.html', products='products') passes a string 'products' instead of the list. render_template('products.html', products=products)" misses the return statement.

3. Final Answer:

   return render_template('products.html', products=products) -> Option B

4. Quick Check:

   Pass list variable with matching name and return it [OK]

Hint: Return render_template with variable name matching template use [OK]

Common Mistakes:

• Passing variable name as string instead of list
• Not returning the render_template call
• Using different variable names without updating template