CSV Handling Exercises

Exercise 1: Count Students in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), counts the total number of students, and prints the count to the console. Handle errors like missing files.

Hint:
Use csv.reader or csv.DictReader to read the file. Loop through the rows to count students, skipping the header.

Solution: See 01_csv_count_students.py.

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Exercise 2: Calculate Average Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), calculates the average age of students, and prints it to the console with two decimal places. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to access the "age" column. Convert "age" to a number and compute the average. Check for empty data.

Solution: See 02_csv_average_age.py.

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Exercise 3: Count Students with Grade A in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds the number of students with grade "A", and prints the count to the console. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to access the "grade" column. Loop through or use a condition to count students with "A". Check for no matches.

Solution: See 03_csv_count_grade_a.py.

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Exercise 4: Find Students Over 20 in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds the names of students whose age is over 20, and prints each name on a new line to the console. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to access "name" and "age". Convert "age" to a number and filter based on the condition. Check for no matches.

Solution: See 04_csv_over_20.py.

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Exercise 5: Find Oldest Student in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds the student with the highest age, and prints their name and age to the console. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to access "name" and "age". Convert "age" to a number and find the maximum using max() or a loop. Check for empty data.

Solution: See 05_csv_oldest_student.py.

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Exercise 6: Sort Students by Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), sorts the students by age (ascending), and saves the sorted data to a new file sorted_students.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Convert "age" to a number and sort with sorted(). Check for empty data.

Solution: See 06_csv_sort_by_age.py.

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Exercise 7: Filter Students with Grade A in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), filters out students with grade "A", and saves their data to a new file grade_a_students.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Filter students with a condition or filter(). Check for no matches.

Solution: See 07_csv_grade_a.py.

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Exercise 8: Count Students by Grade in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), counts the number of students per grade, and saves the counts to a new file grade_counts.csv with columns "grade" and "count". Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Count grades with a dictionary or collections.Counter. Check for empty data.

Solution: See 08_csv_grade_counts.py.

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Exercise 9: Filter Teen Students in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds students aged 18 to 20 (inclusive), and saves their data to a new file teen_students.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Convert "age" to a number and filter with a condition or filter(). Check for no matches.

Solution: See 09_csv_teen_students.py.

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Exercise 10: Calculate Average Age by Grade in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), calculates the average age for each grade, and saves the results to a new file grade_age_averages.csv with columns "grade" and "average_age" (rounded to two decimal places). Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Track sums and counts per grade in a dictionary and compute averages. Check for empty data.

Solution: See 10_csv_grade_age_averages.py.

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Exercise 11: Filter Students Above Average Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds students whose age is above the overall average age, and saves their data to a new file above_average_age.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Calculate the average age first, then filter students. Check for empty data.

Solution: See 11_csv_above_average_age.py.

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Exercise 12: Filter Top Performers Above Average Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds students whose age is above the overall average age and have a grade of "A", and saves their data to a new file top_performers.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Calculate the average age, then filter with a combined condition. Check for empty data or no matches.

Solution: See 12_csv_top_performers.py.

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Exercise 13: Find Youngest Student per Grade in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds the youngest student for each grade, and saves their data to a new file youngest_per_grade.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Track the youngest per grade in a dictionary or with a loop. Check for empty data.

Solution: See 13_csv_youngest_per_grade.py.

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Exercise 14: Filter Students Above Grade Average Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds students whose age is above the average age of their grade, and saves their data to a new file above_grade_average.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Calculate average age per grade, then filter students. Check for empty data.

Solution: See 14_csv_above_grade_average.py.

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Exercise 15: Find Students Closest to Grade Average Age in CSV

Question:
Write a Python program that reads the file students.csv (assume it’s a CSV file with columns "name", "age", "grade"), finds the student closest to the average age for each grade, and saves their data to a new file closest_to_grade_average.csv. Handle errors like missing files or invalid data.

Hint:
Use csv.DictReader to read and csv.DictWriter to write. Calculate average age per grade, then compare distances with abs(age - average). Pick the first if tied.

Solution: See 15_csv_closest_to_grade_average.py.

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