How to Check Data Type

In Pandas, you can check the data type of a column to determine if it is numeric or string (or any other type). This is useful for ensuring that operations are performed on the correct data types.

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Checking Data Types with dtype

You can use the dtype attribute to inspect the data type of a column:

import pandas as pd

# Create a DataFrame
data = {
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Age': [25, 30, 35],
    'City': ['New York', 'Los Angeles', 'Chicago']
}

df = pd.DataFrame(data)

# Check if a column is numeric
print(df['Age'].dtype)
# Check if a column is string (object type in Pandas)
print(df['Name'].dtype)

Output:

int64
object

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Using pd.api.types for Type Checking

Pandas provides utility functions in pd.api.types to check for specific data types:

pes:

from pandas.api.types import is_numeric_dtype, is_string_dtype

# Check if the 'Age' column is numeric
print(is_numeric_dtype(df['Age']))

# Check if the 'Name' column is a string
print(is_string_dtype(df['Name']))

Output:

True
True

Use Cases

1. Data Validation: Ensure columns contain the expected data type before performing operations.

2. Conditional Logic: Apply different logic based on the column's data type.

   Example:

   def process_column(column):
       if is_numeric_dtype(column):
           return column.mean()  # Calculate the mean for numeric columns
       elif is_string_dtype(column):
           return column.value_counts()  # Get value counts for string columns
   
   print(process_column(df['Age']))
   print(process_column(df['Name']))

   Output:

   30.0
   Alice      1
   Bob        1
   Charlie    1
   dtype: int64

   By checking the data type of columns, you can write robust and flexible code that handles different types of data effectively.