Author: Prince PARK

# Calculate the number of empty cells in each column
# The following line consists of three commands. Try
# to think about how they work together to calculate
# the number of missing entries per column
missing_data = dataset.isnull().sum().to_frame()

# Rename column holding the sums
missing_data = missing_data.rename(columns={0:'Empty Cells'})

# Print the results
print(missing_data)

## OR 
print(dataset.isnull().sum().to_frame().rename(columns={0:'Empty Cells'}))

# Show the missing value rows
dataset[dataset.isnull().any(axis=1)]

import pandas as pd

# Load data from a text file
!wget https://raw.githubusercontent.com/MicrosoftDocs/mslearn-introduction-to-machine-learning/main/Data/ml-basics/grades.csv
df_students = pd.read_csv('grades.csv',delimiter=',',header='infer')

# Remove any rows with missing data
df_students = df_students.dropna(axis=0, how='any')

# Calculate who passed, assuming '60' is the grade needed to pass
passes  = pd.Series(df_students['Grade'] >= 60)

# Save who passed to the Pandas dataframe
df_students = pd.concat([df_students, passes.rename("Pass")], axis=1)

# Create a figure for 2 subplots (1 row, 2 columns)
fig, ax = plt.subplots(1, 2, figsize = (10,4))

# Create a bar plot of name vs grade on the first axis
ax[0].bar(x=df_students.Name, height=df_students.Grade, color='orange')
ax[0].set_title('Grades')
ax[0].set_xticklabels(df_students.Name, rotation=90)

# Create a pie chart of pass counts on the second axis
pass_counts = df_students['Pass'].value_counts()
ax[1].pie(pass_counts, labels=pass_counts)
ax[1].set_title('Passing Grades')
ax[1].legend(pass_counts.keys().tolist())

# Add a title to the Figure
fig.suptitle('Student Data')

# Show the figure
fig.show()

# Create a function that we can re-use
# Create a function that we can re-use
def show_distribution_with_quantile(var_data, quantile = 0):
    '''
    This function will make a distribution (graph) and display it
    '''

    if(quantile > 0){
        # calculate the quantile percentile
        q01 = var_data.quantile(quantile) 
        print(f"quantile = {q01}")

        var_data = var_data[var_data>q01]
    }

    # Get statistics
    min_val = var_data.min()
    max_val = var_data.max()
    mean_val = var_data.mean()
    med_val = var_data.median()
    mod_val = var_data.mode()[0]

    print('Minimum:{:.2f}\nMean:{:.2f}\nMedian:{:.2f}\nMode:{:.2f}\nMaximum:{:.2f}\n'.format(min_val,
                                                                                            mean_val,
                                                                                            med_val,
                                                                                            mod_val,
                                                                                            max_val))

    # Create a figure for 2 subplots (2 rows, 1 column)
    fig, ax = plt.subplots(2, 1, figsize = (10,4))

    # Plot the histogram   
    ax[0].hist(var_data)
    ax[0].set_ylabel('Frequency')

    # Add lines for the mean, median, and mode
    ax[0].axvline(x=min_val, color = 'gray', linestyle='dashed', linewidth = 2)
    ax[0].axvline(x=mean_val, color = 'cyan', linestyle='dashed', linewidth = 2)
    ax[0].axvline(x=med_val, color = 'red', linestyle='dashed', linewidth = 2)
    ax[0].axvline(x=mod_val, color = 'yellow', linestyle='dashed', linewidth = 2)
    ax[0].axvline(x=max_val, color = 'gray', linestyle='dashed', linewidth = 2)

    # Plot the boxplot   
    ax[1].boxplot(var_data, vert=False)
    ax[1].set_xlabel('Value')

    # Add a title to the Figure
    fig.suptitle('Data Distribution')

    # Show the figure
    fig.show()

# Get the variable to examine
col = df_students['Grade']
# Call the function
show_distribution(col)

def show_density(var_data):
    fig = plt.figure(figsize=(10,4))

    # Plot density
    var_data.plot.density()

    # Add titles and labels
    plt.title('Data Density')

    # Show the mean, median, and mode
    plt.axvline(x=var_data.mean(), color = 'cyan', linestyle='dashed', linewidth = 2)
    plt.axvline(x=var_data.median(), color = 'red', linestyle='dashed', linewidth = 2)
    plt.axvline(x=var_data.mode()[0], color = 'yellow', linestyle='dashed', linewidth = 2)

    # Show the figure
    plt.show()

# Get the density of StudyHours
show_density(col)

data_storage_account_name = '<data_storage_account_name>'
data_storage_account_key = '<data_storage_account_key>'

data_mount_point = '/mnt/data'

data_file_path = '/bronze/wwi-factsale.csv'

dbutils.fs.mount(
  source = f"wasbs://dev@{data_storage_account_name}.blob.core.windows.net",
  mount_point = data_mount_point,
  extra_configs = {f"fs.azure.account.key.{data_storage_account_name}.blob.core.windows.net": data_storage_account_key})

display(dbutils.fs.ls("/mnt/data"))
#this path is available as dbfs:/mnt/data for spark APIs, e.g. spark.read
#this path is available as file:/dbfs/mnt/data for regular APIs, e.g. os.listdir

# %fs magic command - for accessing the dbutils filesystem module. Most dbutils.fs commands are available using %fs magic commands