Data Analytics
Perfect channel to learn Data Analytics Learn SQL, Python, Alteryx, Tableau, Power BI and many more For Promotions: @coderfun @love_data
Mostrar más📈 Análisis del canal de Telegram Data Analytics
El canal Data Analytics (@sqlspecialist) en el segmento lingüístico de Inglés es un actor destacado. Actualmente la comunidad reúne a 109 605 suscriptores, ocupando la posición 1 124 en la categoría Tecnologías y Aplicaciones y el puesto 2 373 en la región India.
📊 Métricas de audiencia y dinámica
Desde su creación el невідомо, el proyecto ha mostrado un crecimiento acelerado, reuniendo a 109 605 suscriptores.
Según los últimos datos del 19 junio, 2026, el canal mantiene una actividad estable. En los últimos 30 días la variación de miembros fue de 624, y en las últimas 24 horas de -15, conservando un alto alcance.
- Estado de verificación: No verificado
- Tasa de interacción (ER): El promedio de interacción de la audiencia es 3.26%. Durante las primeras 24 horas tras publicar, el contenido suele obtener 1.27% de reacciones respecto al total de suscriptores.
- Alcance de las publicaciones: Cada publicación recibe en promedio 3 575 visualizaciones. En el primer día suele acumular 1 388 visualizaciones.
- Reacciones e interacción: La audiencia responde de forma activa: el promedio de reacciones por publicación es 9.
- Intereses temáticos: El contenido se centra en temas clave como row, sql, analytic, analyst, visualization.
📝 Descripción y política de contenido
El autor describe el recurso como un espacio para expresar opiniones subjetivas:
“Perfect channel to learn Data Analytics
Learn SQL, Python, Alteryx, Tableau, Power BI and many more
For Promotions: @coderfun @love_data”
Gracias a la alta frecuencia de actualizaciones (últimos datos recibidos el 20 junio, 2026), el canal mantiene la vigencia y un amplio alcance. La analítica demuestra que la audiencia interactúa activamente con el contenido, lo que lo convierte en un punto de referencia dentro de la categoría Tecnologías y Aplicaciones.
SELECT department, COUNT(*)
FROM employees
WHERE salary > 50000
GROUP BY department
HAVING COUNT(*) > 5
ORDER BY COUNT(*) DESC
LIMIT 10;
💡 Note: Even though SELECT comes first when we write SQL, it's processed after WHERE, GROUP BY, and HAVING—knowing this prevents sneaky bugs!
💬 Tap ❤️ if this helped clarify things!import numpy as np
def remove_outliers(data):
q1 = np.percentile(data, 25)
q3 = np.percentile(data, 75)
iqr = q3 - q1
lower = q1 - 1.5 * iqr
upper = q3 + 1.5 * iqr
return [x for x in data if lower <= x <= upper]
2️⃣ Convert a nested list to a flat list.
nested = [[1, 2], [3, 4],]
flat = [item for sublist in nested for item in sublist]
3️⃣ Read a CSV file and count rows with nulls.
import pandas as pd
df = pd.read_csv('data.csv')
null_rows = df.isnull().any(axis=1).sum()
print("Rows with nulls:", null_rows)
4️⃣ How do you handle missing data in pandas?
⦁ Drop missing rows: df.dropna()
⦁ Fill missing values: df.fillna(value)
⦁ Check missing data: df.isnull().sum()
5️⃣ Explain the difference between loc[] and iloc[].
⦁ loc[]: Label-based indexing (e.g., row/column names)
Example: df.loc[0, 'Name']
⦁ iloc[]: Position-based indexing (e.g., row/column numbers)
Example: df.iloc
💬 Tap ❤️ for more!SELECT MAX(salary)
FROM employee
WHERE salary < (SELECT MAX(salary) FROM employee);
2️⃣ Get the top 3 products by revenue from sales table.
SELECT product_id, SUM(revenue) AS total_revenue
FROM sales
GROUP BY product_id
ORDER BY total_revenue DESC
LIMIT 3;
3️⃣ Use JOIN to combine customer and order data.
SELECT c.customer_name, o.order_id, o.order_date
FROM customers c
JOIN orders o ON c.customer_id = o.customer_id;
(That's an INNER JOIN—use LEFT JOIN to include all customers, even without orders.)
4️⃣ Difference between WHERE and HAVING?
⦁ WHERE filters rows before aggregation (e.g., on individual records).
⦁ HAVING filters rows after aggregation (used with GROUP BY on aggregates).
Example:
SELECT department, COUNT(*)
FROM employee
GROUP BY department
HAVING COUNT(*) > 5;
5️⃣ Explain INDEX and how it improves performance.
An INDEX is a data structure that improves the speed of data retrieval.
It works like a lookup table and reduces the need to scan every row in a table.
Especially useful for large datasets and on columns used in WHERE, JOIN, or ORDER BY—think 10x faster queries, but it slows inserts/updates a bit.
💬 Tap ❤️ for more!SELECT MAX(salary)
FROM employee
WHERE salary < (SELECT MAX(salary) FROM employee);
2️⃣ Get the top 3 products by revenue from sales table.
SELECT product_id, SUM(revenue) AS total_revenue
FROM sales
GROUP BY product_id
ORDER BY total_revenue DESC
LIMIT 3;
3️⃣ Use JOIN to combine customer and order data.
SELECT c.customer_name, o.order_id, o.order_date
FROM customers c
JOIN orders o ON c.customer_id = o.customer_id;
(That's an INNER JOIN—use LEFT JOIN to include all customers, even without orders.)
4️⃣ Difference between WHERE and HAVING?
⦁ WHERE filters rows before aggregation (e.g., on individual records).
⦁ HAVING filters rows after aggregation (used with GROUP BY on aggregates).
Example:
SELECT department, COUNT(*)
FROM employee
GROUP BY department
HAVING COUNT(*) > 5;
5️⃣ Explain INDEX and how it improves performance.
An INDEX is a data structure that improves the speed of data retrieval.
It works like a lookup table and reduces the need to scan every row in a table.
Especially useful for large datasets and on columns used in WHERE, JOIN, or ORDER BY—think 10x faster queries, but it slows inserts/updates a bit.
💬 Tap ❤️ for more!import sqlite3
conn = sqlite3.connect('data.db')
cursor = conn.cursor()
3️⃣0️⃣ What is the difference between.loc and.iloc in Pandas?
⦁ .loc[] is label-based indexing (e.g., df.loc by row label)
⦁ .iloc[] is position-based indexing (e.g., df.iloc by row number)
💬 Tap ❤️ for Part 5SELECT MAX(salary)
FROM employees
WHERE salary < (SELECT MAX(salary) FROM employees);
6️⃣ What is the difference between INNER JOIN and LEFT JOIN?
⦁ INNER JOIN: Returns only matching rows from both tables.
⦁ LEFT JOIN: Returns all rows from the left table, and matching rows from the right (NULLs if no match).
7️⃣ What are outliers? How do you detect and handle them?
Outliers are values that deviate significantly from the rest of the data.
Detection Methods:
⦁ IQR (Interquartile Range)
⦁ Z-score
Handling Methods:
⦁ Remove outliers
⦁ Cap values
⦁ Use transformation (e.g., log scale)
8️⃣ What is a Pivot Table?
A pivot table is a data summarization tool that allows quick grouping, aggregation, and analysis of data in spreadsheets or BI tools. It's useful for analyzing patterns and trends.
9️⃣ How do you validate a data model?
⦁ Split data into training and testing sets
⦁ Use cross-validation (e.g., k-fold)
⦁ Evaluate metrics like Accuracy, Precision, Recall, F1-Score, RMSE, etc.
🔟 What is Hypothesis Testing? Difference between t-test and z-test?
Hypothesis testing is a statistical method to test assumptions about a population.
⦁ T-test: Used when sample size is small and population variance is unknown.
⦁ Z-test: Used when sample size is large or population variance is known.
💬 Tap ❤️ for Part 2!
¡Ya disponible! Investigación de Telegram 2025 — los principales insights del año 
