w3resource

Add new record to NumPy Structured array

NumPy: Structured Arrays Exercise-4 with Solution

Adding New Records:

Write a NumPy program that adds a new record to the structured array created array with fields for 'name' (string), 'age' (integer), and 'height' (float) with the fields: 'name': ' Nela Suna ', 'age': 25, 'height': 5.9.

Sample Solution:

Python Code:

import numpy as np

# Define the data type for the structured array
dtype = [('name', 'U10'), ('age', 'i4'), ('height', 'f4')]

# Create the structured array with sample data
structured_array = np.array([
    ('Lehi Piero', 25, 5.5),
    ('Albin Achan', 30, 5.8),
    ('Zerach Hava', 35, 6.1),
    ('Edmund Tereza', 40, 5.9),
    ('Laura Felinus', 28, 5.7)
], dtype=dtype)

print("Original Structured Array:")
print(structured_array)

# Define the new record to be added
new_record = np.array([('Nela Suna', 25, 5.9)], dtype=dtype)

# Add the new record to the structured array
# Use np.append to concatenate the new record to the existing array
updated_array = np.append(structured_array, new_record)

# Print the updated structured array
print("\nUpdated Structured Array:")
print(updated_array)

Output:

Original Structured Array:
[('Lehi Piero', 25, 5.5) ('Albin Acha', 30, 5.8) ('Zerach Hav', 35, 6.1)
 ('Edmund Ter', 40, 5.9) ('Laura Feli', 28, 5.7)]

Updated Structured Array:
[('Lehi Piero', 25, 5.5) ('Albin Acha', 30, 5.8) ('Zerach Hav', 35, 6.1)
 ('Edmund Ter', 40, 5.9) ('Laura Feli', 28, 5.7) ('Nela Suna', 25, 5.9)]

Explanation:

  • Import Libraries:
    • Imported numpy as "np" for array creation and manipulation.
  • Define Data Type:
    • Define the data type for the structured array using a list of tuples. Each tuple specifies a field name and its corresponding data type. The data types are:
      • 'U10' for a string of up to 10 characters.
      • 'i4' for a 4-byte integer.
      • 'f4' for a 4-byte float.
  • Create Structured Array:
    • Created the structured array using np.array(), providing sample data for five individuals. Each individual is represented as a tuple with values for 'name', 'age', and 'height'.
  • Define New Record:
    • Define the new record to be added as a NumPy array with the same data type as the structured array. The new record has the values 'name': 'Arlo Arias', 'age': 25, 'height': 5.9.
  • Add New Record:
    • Used np.append to concatenate the new record to the existing structured array, resulting in an updated array.
  • Print Updated Structured Array:
    • Print the updated structured array to verify the addition of the new record.

Python-Numpy Code Editor: