numpy.trim_zeros() in Python
Last Updated :
21 Jun, 2025
numpy.trim_zeros() removes the leading and trailing zeros from a 1-D array. It is often used to clean up data by trimming unnecessary zeros from the beginning or end of the array. Example:
Python
import numpy as np
a = np.array([0, 0, 3, 4, 0, 5, 0, 0])
res = np.trim_zeros(a)
print(res)
Explanation: np.trim_zeros(a) removes both leading and trailing zeros by default (trim='fb'). Zeros in the middle remain unchanged.
Syntax
numpy.trim_zeros(filt, trim='fb')
Parameter:
- filt (array_like): A 1-D array of numeric values from which zeros will be trimmed.
- trim (str, optional): Indicates which zeros to remove, 'f' for leading (front), 'b' for trailing (back) and 'fb' (default) for both.
Returns: A new 1-D NumPy array with the specified zeros removed.
Examples
Example 1: In this example, we use the parameter trim='f' to remove the leading zeros from the beginning of the array, while keeping the zeros at the end unchanged.
Python
import numpy as np
a = np.array([0, 0, 1, 2, 3, 0])
res = np.trim_zeros(a, trim='f')
print(res)
Explanation: np.trim_zeros(a, trim='f') removes only the leading zeros from the beginning of the array. Trailing zeros are preserved, resulting in [1, 2, 3, 0].
Example 2: In this example, we use the parameter trim='b' to remove the trailing zeros from the end of the array, while keeping the leading zeros at the beginning unchanged.
Python
import numpy as np
a = np.array([0, 1, 2, 0, 0])
res = np.trim_zeros(a, trim='b')
print(res)
Explanation: np.trim_zeros(a, trim='b') removes only the trailing zeros from the end of the array. Leading zeros are kept intact, resulting in [0, 1, 2].
Example 3: In this example, all elements are zeros. Since np.trim_zeros() removes zeros from both ends by default, the result is an empty array.
Python
import numpy as np
a = np.array([0, 0, 0, 0])
res = np.trim_zeros(a)
print(res)
Explanation: np.trim_zeros(a) removes zeros from both ends by default (trim='fb'). Since the array contains only zeros, the result is an empty array.
Explore
Python Fundamentals
Python Data Structures
Advanced Python
Data Science with Python
Web Development with Python
Python Practice
My Profile