详解如何使用Pandas创建有效且可复制的代码

import pandas as pd

# Bad variable name
df1 = pd.read_csv('data.csv')

# Good variable name
sales_data = pd.read_csv('sales_data.csv')

def load_data(file_path):
    return pd.read_csv(file_path)

def clean_data(df):
    df.dropna(inplace=True)
    df['date'] = pd.to_datetime(df['date'])
    return df

# Usage
sales_data = load_data('sales_data.csv')
cleaned_sales_data = clean_data(sales_data)

def load_data(file_path):
    """
    Load data from a CSV file.

    Parameters:
    file_path (str): Path to the CSV file.

    Returns:
    pd.DataFrame: Loaded data as a DataFrame.
    """
    return pd.read_csv(file_path)

def load_data(file_path):
    try:
        return pd.read_csv(file_path)
    except FileNotFoundError:
        print(f"File not found: {file_path}")
        return pd.DataFrame()

def test_load_data():
    df = load_data('sales_data.csv')
    assert not df.empty, "Dataframe should not be empty"

def test_clean_data():
    df = pd.DataFrame({'date': ['2021-01-01', None]})
    cleaned_df = clean_data(df)
    assert cleaned_df['date'].isnull().sum() == 0, "There should be no missing dates after cleaning"