# Let us make some data we will save later
students = [
    {'name': 'Alex', 'age': 18, 'grade': 'A'},
    {'name': 'Ben', 'age': 17, 'grade': 'B'},
    {'name': 'Clara', 'age': 19, 'grade': 'A'},
]

print(students)

import csv  # This module helps us write CSV files

with open('students.csv', mode='w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['name', 'age', 'grade'])
    writer.writeheader()
    writer.writerows(students)

print('CSV file students.csv has been written!')

# Let us check what the CSV file looks like by reading it back.
with open('students.csv', 'r') as file:
    print(file.read())
    

# Let us write the data to an Excel file
from openpyxl import Workbook  # openpyxl works for Excel files

wb = Workbook()
ws = wb.active
ws.append(['name', 'age', 'grade'])  # Add header
for student in students:
    ws.append([student['name'], student['age'], student['grade']])

wb.save('students.xlsx')
print('Excel file students.xlsx has been saved!')

# Let us check that our Excel file exists.
import os
print('students.xlsx exists:', os.path.exists('students.xlsx'))

import json  # Built-in for handling JSON

with open('students.json', 'w') as file:
    json.dump(students, file, indent=2)

print('JSON file students.json has been created!')

# Let us read and print our JSON file
with open('students.json') as file:
    data = json.load(file)
    print(data)
    

# Let us try saving to a protected folder
try:
    with open('/students.csv', 'w') as file:
        file.write('demo')
# Except will run if the above fails
except PermissionError:
    print('Could not write to that location!')
except Exception as e:
    print('Something else went wrong:', e)
    

# Update Clara's grade
for student in students:
    if student['name'] == 'Clara':
        student['grade'] = 'B'

print(students)

# Remove Ben from the list
students = [s for s in students if s['name'] != 'Ben']
print(students)

# Now save the updated list to all three formats again
# CSV
with open('students_updated.csv', 'w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['name', 'age', 'grade'])
    writer.writeheader()
    writer.writerows(students)
# Excel
wb = Workbook()
ws = wb.active
ws.append(['name', 'age', 'grade'])
for student in students:
    ws.append([student['name'], student['age'], student['grade']])
wb.save('students_updated.xlsx')
# JSON
with open('students_updated.json', 'w') as file:
    json.dump(students, file, indent=2)
print('All updated files saved.')

# Filter for A grades, sort by age
top_students = [s for s in students if s['grade'] == 'A']
top_students = sorted(top_students, key=lambda s: s['age'])

with open('top_students.csv', 'w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['name', 'age', 'grade'])
    writer.writeheader()
    writer.writerows(top_students)

print('Top students saved to top_students.csv')

# Install pandas if you do not have it already
!pip install pandas openpyxl

import pandas as pd

df = pd.DataFrame(students)
df.to_csv('students_pandas.csv', index=False)
df.to_excel('students_pandas.xlsx', index=False)
print('Files created with pandas!')

# Get today's mood
from datetime import date
today = str(date.today())
mood = input('How do you feel today? (happy, sad, excited): ')

entry = {'date': today, 'mood': mood}
print(entry)

# Save mood as CSV
with open('mood.csv', 'w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['date', 'mood'])
    writer.writeheader()
    writer.writerow(entry)

# Save as Excel
wb = Workbook()
ws = wb.active
ws.append(['date', 'mood'])
ws.append([entry['date'], entry['mood']])
wb.save('mood.xlsx')

# Save as JSON
with open('mood.json', 'w') as file:
    json.dump(entry, file, indent=2)

print('Your mood is saved in mood.csv, mood.xlsx, and mood.json!')

# Quick check: Try saving an empty list
empty_students = []
with open('empty.csv', 'w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['name', 'age', 'grade'])
    writer.writeheader()
    writer.writerows(empty_students)
print('Empty CSV still works!')