Age
count   5.000000
mean   30.000000
std     6.363961
min    22.000000
25%    26.000000
50%    29.000000
75%    35.000000
max    38.000000

---

10. df.columns
Returns the column labels of the DataFrame.

import pandas as pd
df = pd.DataFrame({'Name': [], 'Age': [], 'City': []})
print(df.columns)

Index(['Name', 'Age', 'City'], dtype='object')

---

11. df.dtypes
Returns the data type of each column.

import pandas as pd
df = pd.DataFrame({'Name': ['Alice'], 'Age': [25], 'Salary': [75000.50]})
print(df.dtypes)

Name       object
Age         int64
Salary    float64
dtype: object

---

12. Selecting a Column
Select a single column, which returns a Pandas Series.

import pandas as pd
data = {'Name': ['Alice', 'Bob'], 'Age': [25, 30]}
df = pd.DataFrame(data)
ages = df['Age']
print(ages)

0    25
1    30
Name: Age, dtype: int64

#DataSelection #Indexing #Statistics

---

13. df.loc[]
Access a group of rows and columns by label(s) or a boolean array.

import pandas as pd
data = {'Age': [25, 30, 35], 'City': ['NY', 'LA', 'CH']}
df = pd.DataFrame(data, index=['Alice', 'Bob', 'Charlie'])
print(df.loc['Bob'])

Age     30
City    LA
Name: Bob, dtype: object

---

14. df.iloc[]
Access a group of rows and columns by integer position(s).

import pandas as pd
data = {'Age': [25, 30, 35], 'City': ['NY', 'LA', 'CH']}
df = pd.DataFrame(data, index=['Alice', 'Bob', 'Charlie'])
print(df.iloc[1]) # Get the second row (index 1)

Age     30
City    LA
Name: Bob, dtype: object

---

15. df.isnull()
Returns a DataFrame of the same shape with boolean values indicating if a value is missing (NaN).

import pandas as pd
import numpy as np
df = pd.DataFrame({'A': [1, np.nan], 'B': [3, 4]})
print(df.isnull())

A      B
0  False  False
1   True  False

---

16. df.dropna()
Removes missing values.

import pandas as pd
import numpy as np
df = pd.DataFrame({'A': [1, np.nan, 3], 'B': [4, 5, 6]})
cleaned_df = df.dropna()
print(cleaned_df)

A  B
0  1.0  4
2  3.0  6

#DataCleaning #MissingData

---

17. df.fillna()
Fills missing (NaN) values with a specified value or method.

import pandas as pd
import numpy as np
df = pd.DataFrame({'Score': [90, 85, np.nan, 92]})
filled_df = df.fillna(0)
print(filled_df)

Score
0   90.0
1   85.0
2    0.0
3   92.0

---

18. df.drop_duplicates()
Removes duplicate rows from the DataFrame.

import pandas as pd
data = {'Name': ['Alice', 'Bob', 'Alice'], 'Age': [25, 30, 25]}
df = pd.DataFrame(data)
unique_df = df.drop_duplicates()
print(unique_df)

Name  Age
0  Alice   25
1    Bob   30

---

19. df.rename()
Alters axes labels (e.g., column names).

import pandas as pd
df = pd.DataFrame({'A': [1], 'B': [2]})
renamed_df = df.rename(columns={'A': 'Column_A', 'B': 'Column_B'})
print(renamed_df)

Column_A  Column_B
0         1         2

---

20. series.value_counts()
Returns a Series containing counts of unique values.