如何用Python正确提取列表中大于m且小于n的元素？

Hey there! Let's walk through the issues in your code and get it working correctly for your requirement.

Key Issues in the Original Code #

• Syntax Error in Boolean Indexing: The line final_array =array_1[array_1>m array_1<n] is missing a logical operator. For numpy array boolean indexing, you need to use & (logical AND) to combine conditions, and wrap each condition in parentheses (due to operator precedence rules).
• Output Format Mismatch: Your code returns a numpy array, but the example expects a standard Python list. You'll need to convert the numpy result to a list.
• Unnecessary Dependency: While numpy works, this task can be achieved more simply with native Python, no external libraries required.

Corrected Version Using Numpy #

If you want to stick with numpy, here's the fixed code:

import ast
import numpy as np  # Move imports to the top for better code structure

input_list = ast.literal_eval(input())
m = int(input())
n = int(input())

array_1 = np.array(input_list)
# Fix the boolean indexing with proper operator and parentheses
final_array = array_1[(array_1 > m) & (array_1 < n)]
# Convert numpy array to Python list to match the example output format
print(final_array.tolist())

Simpler Native Python Implementation (Recommended) #

This approach avoids numpy entirely and uses a list comprehension, which is more lightweight and readable for this task:

import ast

input_list = ast.literal_eval(input())
m = int(input())
n = int(input())

# List comprehension to filter elements between m and n
final_list = [num for num in input_list if m < num < n]
print(final_list)

Test with Example Input #

Example Input:
Enter the array: [1, 5, 9, 12, 15, 7, 12, 9]
Enter m: 6
Enter n: 12

Both versions will output: [9, 7, 9], which matches the expected result perfectly.

内容的提问来源于stack exchange，提问作者Tejas Jadhao