Python Pandas: Find the length of the string in dataframe

9.0K Asked by IraJoshi in Python , Asked on Apr 14, 2021

How to find find the length of dataframe string stored in each cell. What code should I use to do this?

To find the length of strings in a data frame you have the len method on the dataframes str property. But to do this you need to call this method on the column that contains the string data.

You can find the length of dataframe using the below code:

import pandas as pd

data = pd.DataFrame({

    'age' : [15, 17, 20, 14, 25],

    'name': ["Sample", "New User", "My Name", "Jane Doe", "John Doe"]

})

data['name'].str.len()

You'll get the following output:

0    6

1    8

2    7

3    8

4    8

Name: name, dtype: int64

Your Answer

Answers (2)

Ranjana

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.

2 Weeks

Ranjana

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.

10 Months