Python Week 6: Our Programs Finally Read Real Files

name = "  amina WAWERU  "

print(name.strip())       # remove leading/trailing spaces
print(name.lower())       # all lowercase
print(name.upper())       # all uppercase
print(name.title())       # Title Case - first letter of each word
print(name.strip().title())  # chain them together

amina WAWERU
  amina waweru  
  AMINA WAWERU  
  Amina Waweru  
Amina Waweru

course = "  data engineering "

print(course.strip())              # "data engineering"
print(course.strip().title())      # "Data Engineering"
print(course.strip().replace("engineering", "science"))  # "data science"
print("Data Engineering".startswith("Data"))    # True
print("Data Engineering".endswith("ing"))       # True
print("Data Engineering".count("a"))            # 2
print("Data Engineering".split(" "))            # ['Data', 'Engineering']

data engineering
Data Engineering
data science
True
True
2
['Data', 'Engineering']

score_input = "88"
name_input = "Amina123"
empty_input = "   "

print(score_input.isdigit())      # True - all digits
print(name_input.isalpha())       # False - has numbers
print(empty_input.strip() == "")  # True - effectively empty
print("amina@lux.co.ke".find("@"))  # 5 - position of @

True
False
True
5

def validate_student_input(name, score_str):
    errors = []

    if not name.strip():
        errors.append("Name cannot be empty")
    if not score_str.isdigit():
        errors.append("Score must be a whole number")
    elif not (0 <= int(score_str) <= 100):
        errors.append("Score must be between 0 and 100")

    return errors

# Test it
print(validate_student_input("Amina", "88"))      # []
print(validate_student_input("", "88"))            # ['Name cannot be empty']
print(validate_student_input("Brian", "abc"))      # ['Score must be a whole number']
print(validate_student_input("Njeri", "150"))      # ['Score must be between 0 and 100']

[]
['Name cannot be empty']
['Score must be a whole number']
['Score must be between 0 and 100']

with open("greeting.txt", "r") as file:
    content = file.read()
    print(content)

with open("notes.txt", "w") as file:
    file.write("Python Week 6 Notes\n")
    file.write("Topic: File Handling\n")
    file.write("Status: Mind blown\n")

print("File written!")

File written!

with open("notes.txt", "r") as file:
    for line in file:
        print(line.strip())    # .strip() removes the \n at the end of each line

Python Week 6 Notes
Topic: File Handling
Status: Mind blown

name,course,score
amina waweru,data engineering,88
BRIAN OTIENO,Data Science,74
njeri kamau ,DATA ENGINEERING,91
kamau mwangi,data science,
wanjiku achieng,Data Engineering,79
aisha baraka,DATA SCIENCE,85

with open("students.csv", "r") as file:
    header = file.readline()    # skip the header row
    print(f"Columns: {header.strip()}")

    for line in file:
        row = line.strip().split(",")
        print(row)

Columns: name,course,score
['amina waweru', 'data engineering', '88']
['BRIAN OTIENO', 'Data Science', '74']
['njeri kamau ', 'DATA ENGINEERING', '91']
['kamau mwangi', 'data science', '']
['wanjiku achieng', 'Data Engineering', '79']
['aisha baraka', 'DATA SCIENCE', '85']

def clean_name(name):
    return name.strip().title()

def clean_course(course):
    return course.strip().title()

def parse_score(score_str):
    score_str = score_str.strip()
    if score_str.isdigit():
        return int(score_str)
    return None   # missing or invalid score

def calculate_grade(score):
    if score is None: return "N/A"
    if score >= 80: return "A"
    elif score >= 70: return "B"
    elif score >= 60: return "C"
    elif score >= 50: return "D"
    else: return "F"

# Read and process the file
students = []

with open("students.csv", "r") as file:
    file.readline()   # skip header

    for line in file:
        parts = line.strip().split(",")
        if len(parts) != 3:
            continue  # skip malformed rows

        name   = clean_name(parts[0])
        course = clean_course(parts[1])
        score  = parse_score(parts[2])
        grade  = calculate_grade(score)

        students.append({
            "name": name,
            "course": course,
            "score": score,
            "grade": grade
        })

# Print the cleaned report
print(f"\n{'='*55}")
print(f"  LUX ACADEMY - CLEANED STUDENT REPORT")
print(f"{'='*55}")
print(f"  {'NAME':<20} {'COURSE':<20} {'SCORE':<7} GRADE")
print(f"  {'-'*50}")

for s in students:
    score_display = str(s['score']) if s['score'] is not None else "MISSING"
    print(f"  {s['name']:<20} {s['course']:<20} {score_display:<7} {s['grade']}")

print(f"{'='*55}")

# Summary
valid_scores = [s['score'] for s in students if s['score'] is not None]
print(f"\n  Total students : {len(students)}")
print(f"  Missing scores : {len(students) - len(valid_scores)}")
print(f"  Class average  : {sum(valid_scores)/len(valid_scores):.1f}")
print(f"  Highest score  : {max(valid_scores)}")
print(f"  Lowest score   : {min(valid_scores)}")

=======================================================
  LUX ACADEMY - CLEANED STUDENT REPORT
=======================================================
  NAME                 COURSE               SCORE   GRADE
  --------------------------------------------------
  Amina Waweru         Data Engineering     88      A
  Brian Otieno         Data Science         74      B
  Njeri Kamau          Data Engineering     91      A
  Kamau Mwangi         Data Science         MISSING N/A
  Wanjiku Achieng      Data Engineering     79      B
  Aisha Baraka         Data Science         85      A
=======================================================

  Total students : 6
  Missing scores : 1
  Class average  : 83.4
  Highest score  : 91
  Lowest score   : 74

with open("cleaned_students.csv", "w") as output:
    output.write("name,course,score,grade\n")

    for s in students:
        score_str = str(s['score']) if s['score'] is not None else ""
        output.write(f"{s['name']},{s['course']},{score_str},{s['grade']}\n")

print("Cleaned data saved to cleaned_students.csv ✅")

Cleaned data saved to cleaned_students.csv ✅

# 1. Write a program that asks for 3 lines of text and saves them to a file called "notes.txt"
# 2. Read "notes.txt" back and print each line numbered (1. line one, 2. line two...)
# 3. Clean this list of messy names using string methods:
#    names = ["  AMINA waweru", "brian OTIENO  ", "NJERI kamau  "]

# Write a function that reads a text file and returns:
# - Total number of lines
# - Total number of words
# - The longest line

def analyse_file(filename):
    pass  # your code here

# Test with any .txt file you create

# Build a contact book that saves to and loads from a CSV file
# contacts.csv format: name,phone,email
#
# Your program should:
# 1. Load existing contacts from file on startup
# 2. Allow adding new contacts
# 3. Allow searching by name
# 4. Save all contacts back to the file on exit
#
# Bonus: validate that the email contains "@" and the phone is digits only

try:
    score = int(input("Enter score: "))
    print(f"Score accepted: {score}")
except ValueError:
    print("That's not a number. Please enter a valid score.")
except FileNotFoundError:
    print("File not found. Check the filename and try again.")
finally:
    print("Validation complete.")