Reading test data from CSV in Selenium Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open the CSV file for reading.

Selenium Python

with open('testdata.csv', [1]) as file:
    reader = csv.reader(file)
    for row in reader:
        print(row)

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

A'x'

B'w'

C'r'

D'a'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'w' or 'a' mode which are for writing or appending, not reading.

The mode 'r' opens the file for reading, which is needed to read test data from CSV.

2fill in blank

medium

Complete the code to import the module needed to read CSV files.

Selenium Python

[1]

with open('testdata.csv', 'r') as file:
    reader = csv.reader(file)
    for row in reader:
        print(row)

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

Aimport os

Bimport csv

Cimport sys

Dimport json

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated modules like os or json.

The csv module is needed to read CSV files in Python.

3fill in blank

hard

Fix the error in the code to read CSV data and print the first column of each row.

Selenium Python

with open('testdata.csv', 'r') as file:
    reader = csv.reader(file)
    for row in reader:
        print(row[1])

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

A<0>

B(0)

C{0}

D[0]

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses or braces which cause syntax errors.

To access the first element of a list in Python, use square brackets with index 0.

4fill in blank

hard

Fill both blanks to read CSV data into a list of dictionaries using DictReader.

Selenium Python

with open('testdata.csv', [1]) as file:
    reader = csv.[2](file)
    data = [row for row in reader]
    print(data)

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

A'r'

B'w'

Creader

DDictReader

Attempts:

3 left

💡 Hint

Common Mistakes

Using write mode or csv.reader instead of DictReader.

Open the file in read mode 'r' and use csv.DictReader to read rows as dictionaries.

5fill in blank

hard

Fill all three blanks to read CSV data and assert the first row's 'username' is 'admin'.

Selenium Python

with open('testdata.csv', [1]) as file:
    reader = csv.DictReader(file)
    rows = list(reader)
    assert rows[[2]]['[3]'] == 'admin'

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

A'r'

B0

Cusername

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong file mode, wrong index, or wrong dictionary key.

Open file in read mode 'r', access first row with index 0, and check 'username' key equals 'admin'.

Practice

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

easy

A. It allows running tests with multiple sets of data without changing the code.

B. It makes the test run faster by using CSV format.

C. It automatically fixes bugs in the test code.

D. It encrypts the test data for security.

Solution

1. Step 1: Understand the purpose of external test data

   Using CSV files lets you separate test data from test code, making tests flexible.

2. Step 2: Identify the benefit in test execution

   With CSV, you can run the same test multiple times with different inputs easily.

3. Final Answer:

   It allows running tests with multiple sets of data without changing the code. -> Option A

4. Quick Check:

   CSV externalizes data = flexible tests [OK]

Hint: CSV stores data separately for easy test reuse [OK]

Common Mistakes:

• Thinking CSV speeds up test execution
• Believing CSV fixes code bugs automatically
• Assuming CSV encrypts data

2. Which Python code snippet correctly opens a CSV file named data.csv for reading test data?

easy

A. file = open('data.csv', 'w')

B. file = open('data.csv', 'r')

C. file = open('data.csv', 'a')

D. file = open('data.csv')

Solution

1. Step 1: Identify the correct file mode for reading

   To read a file, use mode 'r' which stands for read-only.

2. Step 2: Check the options

   file = open('data.csv', 'r') uses 'r' mode correctly; others use write ('w'), append ('a'), or default mode which may not be explicit.

3. Final Answer:

   file = open('data.csv', 'r') -> Option B

4. Quick Check:

   Read mode = 'r' [OK]

Hint: Use 'r' mode to open files for reading [OK]

Common Mistakes:

• Using 'w' which overwrites the file
• Using 'a' which appends instead of reading
• Not specifying mode explicitly

3. Given the CSV file users.csv with content:

username,password
alice,pass123
bob,secure456

What will the output of this code be?

import csv
with open('users.csv', 'r') as file:
    reader = csv.reader(file)
    for row in reader:
        print(row)

medium

A. ('username', 'password')
('alice', 'pass123')
('bob', 'secure456')

B. username,password
alice,pass123
bob,secure456

C. Error: csv.reader cannot read files

D. ['username', 'password']
['alice', 'pass123']
['bob', 'secure456']

Solution

1. Step 1: Understand csv.reader output

   csv.reader reads each line as a list of strings split by commas.

2. Step 2: Analyze the print output

   Each row prints as a list, so header and data rows print as lists of strings.

3. Final Answer:

   ['username', 'password'] ['alice', 'pass123'] ['bob', 'secure456'] -> Option D

4. Quick Check:

   csv.reader returns lists per row [OK]

Hint: csv.reader returns list of strings per row [OK]

Common Mistakes:

• Expecting strings instead of lists
• Confusing tuples with lists
• Thinking csv.reader raises error on valid files

4. What is wrong with this code snippet that reads CSV data for Selenium tests?

import csv
file = open('testdata.csv')
reader = csv.reader(file)
for row in reader:
    print(row)
file.close()

medium

A. The file is not opened in read mode explicitly.

B. The file is not closed after reading.

C. Using open() without a context manager can cause resource leaks.

D. csv.reader cannot be used with open() function.

Solution

1. Step 1: Check file handling best practices

   Using open() without 'with' can cause the file to remain open if errors occur.

2. Step 2: Identify the issue in the code

   Though file.close() is called, if an error happens before, file may not close properly.

3. Final Answer:

   Using open() without a context manager can cause resource leaks. -> Option C

4. Quick Check:

   Use 'with' to auto-close files [OK]

Hint: Always use 'with' to open files safely [OK]

Common Mistakes:

• Thinking file.close() always prevents leaks
• Believing csv.reader can't work with open()
• Ignoring explicit read mode is optional

5. You want to run a Selenium test multiple times using usernames and passwords stored in credentials.csv. Which code snippet correctly reads the CSV and uses the data in a test function?

hard

A. import csv
with open('credentials.csv', 'r') as file:
reader = csv.DictReader(file)
for row in reader:
username = row['username']
password = row['password']
test_login(username, password)

B. import csv
file = open('credentials.csv', 'r')
reader = csv.reader(file)
for row in reader:
test_login(row[0], row[1])
file.close()

C. import csv
with open('credentials.csv') as file:
reader = csv.reader(file)
for row in reader:
test_login(row['username'], row['password'])

D. import csv
with open('credentials.csv', 'r') as file:
reader = csv.reader(file)
for row in reader:
test_login(row[0], row[1])

Solution

1. Step 1: Choose correct CSV reading method for named columns

   csv.DictReader reads CSV rows as dictionaries with column names as keys.

2. Step 2: Use dictionary keys to access username and password

   Accessing row['username'] and row['password'] matches CSV headers and passes correct data.

3. Final Answer:

   Using csv.DictReader and accessing row['username'] and row['password'] correctly. -> Option A

4. Quick Check:

   DictReader + keys = clean data access [OK]

Hint: Use csv.DictReader for named column access [OK]

Common Mistakes:

• Using csv.reader but accessing row by keys
• Not closing files without 'with' block
• Forgetting to specify read mode explicitly