Python Pandas: Find the length of the string in dataframe

If you’re working with Pandas in Python and need to find the length of strings in a DataFrame column, here’s how you can do it:

1. Using .str.len() to Get String Length

• Pandas provides the .str.len() function to find the length of each string in a column.
  
• Example: Find String Length in a Column

import pandas as pd  
# Create a sample DataFrame
data = {'Name': ['Alice', 'Bob', 'Charlie', 'David']}
df = pd.DataFrame(data)
# Add a new column with string lengths
df['Name_Length'] = df['Name'].str.len()
print(df)

 This will output:

     Name Name_Length

0   Alice            5
1     Bob            3
2  Charlie           7
3   David            5

2. Handling Missing or Non-String Values

If your DataFrame contains NaN values, you should handle them properly:

  df['Name_Length'] = df['Name'].astype(str).str.len()

 This ensures NaN values don’t cause errors.

3. Applying to Multiple Columns

If you want to apply .str.len() to multiple columns:

  df[['Col1_Length', 'Col2_Length']] = df[['Col1', 'Col2']].astype(str).apply(lambda x: x.str.len())

4. Final Thoughts

•  Use .str.len() to get the string length in a column.
  
•  Convert non-string data using .astype(str) if necessary.
  
•  Works great for text-based data analysis in Pandas.
  

To find the length of strings in a DataFrame column using Python Pandas, you can use the str.len() method. Here's how you can do it:

import pandas as pd
# Create a sample DataFrame
data = {'Name': ['John', 'Alice', 'Bob', 'Charlie'],
        'City': ['New York', 'Los Angeles', 'Chicago', 'Boston']}
df = pd.DataFrame(data)
# Add a new column with the length of strings in the 'Name' column
df['Name_Length'] = df['Name'].str.len()
# Display the DataFrame
print(df)

Output:

     Name         City  Name_Length
0     John     New York            4
1    Alice  Los Angeles            5
2      Bob      Chicago            3
3  Charlie       Boston            7

In this example, we first create a DataFrame with columns 'Name' and 'City'. Then, we use the str.len() method to compute the length of strings in the 'Name' column and assign the result to a new column 'Name_Length'. Finally, we print the DataFrame to see the result.