Reading test data from JSON in Selenium Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main benefit of reading test data from a JSON file in Selenium tests?

It separates test data from test scripts, making tests easier to maintain and reuse with different data sets.

beginner

How do you load JSON data in Python for Selenium tests?

Use Python's built-in json module with json.load() to read JSON data from a file.

beginner

Which Python statement correctly opens a JSON file named data.json for reading?

<pre>import json
with open('data.json', 'r') as file:
    data = json.load(file)</pre>

intermediate

Why is it better to use JSON files for test data instead of hardcoding data in Selenium scripts?

Because JSON files allow easy updates without changing code, support multiple data sets, and improve test clarity.

beginner

What is a common structure of JSON test data for a login test?

A list or dictionary with keys like username and password for each test case.

Which Python module is used to read JSON files for test data?

A os

B csv

C json

D sys

The json module is designed to parse JSON data in Python.

What is the correct way to open a JSON file named testdata.json for reading?

A open('testdata.json', 'x')

B open('testdata.json', 'w')

C open('testdata.json', 'a')

D open('testdata.json', 'r')

Use mode 'r' to open a file for reading.

Why should test data be stored outside Selenium test scripts?

A To make tests slower

B To separate data from code for easier maintenance

C To avoid using JSON files

D To make tests harder to read

Separating data from code improves maintainability and reusability.

Which of these is a valid JSON data type for test data?

A Dictionary (object)

B Function

C Class

D Module

JSON supports objects (dictionaries), arrays, strings, numbers, booleans, and null.

What does json.load(file) do in Python?

A Reads JSON data from a file and converts it to Python objects

B Deletes a JSON file

C Writes JSON data to a file

D Converts Python objects to JSON string

json.load() reads JSON from a file and parses it into Python data types.

Explain how to read test data from a JSON file in a Selenium Python test.

Think about file handling and JSON parsing in Python.

Describe the advantages of using JSON files for test data in automated testing.

Consider maintainability and flexibility.

Practice

1. What is the main benefit of reading test data from a JSON file in Selenium Python tests?

easy

A. It encrypts test data for security.

B. It makes tests run faster by avoiding web interactions.

C. It automatically generates test cases without writing code.

D. It keeps test code clean and makes data easy to update without changing code.

Solution

1. Step 1: Understand test data separation

   Reading test data from JSON separates data from test logic, making code cleaner.

2. Step 2: Recognize flexibility advantage

   Updating test data in JSON does not require changing test scripts, improving flexibility.

3. Final Answer:

   It keeps test code clean and makes data easy to update without changing code. -> Option D

4. Quick Check:

   Data separation = Clean code + Easy updates [OK]

Hint: Separate data from code for easy updates [OK]

Common Mistakes:

• Thinking JSON speeds up test execution
• Believing JSON auto-generates tests
• Confusing data storage with encryption

2. Which Python code snippet correctly reads a JSON file named data.json into a variable test_data?

easy

A. import json
test_data = json.load(open('data.json'))

B. test_data = open('data.json').read()

C. import json
test_data = json.loads('data.json')

D. test_data = json.read('data.json')

Solution

1. Step 1: Identify correct json module usage

   The json.load() function reads JSON from a file object, so open() must be passed to json.load().

2. Step 2: Check syntax correctness

   import json test_data = json.load(open('data.json')) correctly imports json and uses json.load(open('data.json')) to read the file.

3. Final Answer:

   import json\ntest_data = json.load(open('data.json')) -> Option A

4. Quick Check:

   json.load + open(file) = correct JSON read [OK]

Hint: Use json.load() with open() for files [OK]

Common Mistakes:

• Using json.loads() on filename string
• Forgetting to import json module
• Calling non-existent json.read() function

3. Given the JSON file user.json with content:

{"username": "testuser", "password": "pass123"}

and the code:

import json
with open('user.json') as f:
    data = json.load(f)
print(data['username'])

What will be the output?

medium

A. {'username': 'testuser', 'password': 'pass123'}

B. pass123

C. testuser

D. KeyError

Solution

1. Step 1: Load JSON data into dictionary

   The json.load(f) reads the JSON file and converts it into a Python dictionary with keys 'username' and 'password'.

2. Step 2: Access dictionary value by key

   data['username'] accesses the value 'testuser' from the dictionary.

3. Final Answer:

   testuser -> Option C

4. Quick Check:

   data['username'] = 'testuser' [OK]

Hint: Access JSON keys like dictionary keys [OK]

Common Mistakes:

• Printing the whole dictionary instead of key value
• Using wrong key causing KeyError
• Confusing json.load() with json.loads()

4. What is wrong with this code snippet that reads JSON test data?

import json
file = open('data.json')
data = json.load(file)
file.close()
print(data['email'])

Assuming data.json does not contain the key email.

medium

A. The code will raise a KeyError because 'email' key is missing.

B. The print statement syntax is incorrect.

C. The file is not closed properly.

D. json.load() cannot read from open file objects.

Solution

1. Step 1: Understand json.load() behavior

   json.load() correctly reads JSON from an open file object, so no error here.

2. Step 2: Identify missing key issue

   Accessing data['email'] when 'email' key is missing causes a KeyError at runtime.

3. Final Answer:

   The code will raise a KeyError because 'email' key is missing. -> Option A

4. Quick Check:

   Missing key access = KeyError [OK]

Hint: Check keys exist before accessing JSON data [OK]

Common Mistakes:

• Thinking json.load() fails on open files
• Ignoring possible missing keys in JSON
• Assuming file.close() is missing or wrong

5. You want to use JSON test data to fill a login form in Selenium Python. The JSON file login.json contains:

{"username": "user1", "password": "pass1"}

Which code snippet correctly reads the JSON and uses Selenium to fill the form fields with ids user and pass?

hard

A. import json
with open('login.json') as f:
data = json.load(f)
driver.find_element_by_name('user').send_keys(data['username'])
driver.find_element_by_name('pass').send_keys(data['password'])

B. import json
with open('login.json') as f:
data = json.load(f)
driver.find_element('id', 'user').send_keys(data['username'])
driver.find_element('id', 'pass').send_keys(data['password'])

C. import json
with open('login.json') as f:
data = json.loads(f)
driver.find_element_by_id('user').send_keys(data['username'])
driver.find_element_by_id('pass').send_keys(data['password'])

D. import json
with open('login.json') as f:
data = json.load(f)
driver.find_element('name', 'user').send_keys(data['username'])
driver.find_element('name', 'pass').send_keys(data['password'])

Solution

1. Step 1: Correctly read JSON file

   json.load(f) reads JSON from file object correctly; json.loads() expects a string, so import json with open('login.json') as f: data = json.loads(f) driver.find_element_by_id('user').send_keys(data['username']) driver.find_element_by_id('pass').send_keys(data['password']) is wrong.

2. Step 2: Use correct Selenium locator method

   driver.find_element('id', 'user') is the modern syntax to find element by id; find_element_by_id() is deprecated.

3. Step 3: Match locators with element ids

   The form fields have ids 'user' and 'pass', so locating by id is correct, not by name.

4. Final Answer:

   import json with open('login.json') as f: data = json.load(f) driver.find_element('id', 'user').send_keys(data['username']) driver.find_element('id', 'pass').send_keys(data['password']) -> Option B

5. Quick Check:

   json.load + find_element('id', ...) = correct usage [OK]

Hint: Use json.load() and find_element('id', ...) for form filling [OK]

Common Mistakes:

• Using json.loads() on file object
• Using deprecated find_element_by_id()
• Using wrong locator type (name instead of id)