python中abs什么意思 python绝对值函数abs的应用场景

# 计算两个数之间的绝对距离
num1 = -5
num2 = 3
distance = abs(num1 - num2)
print(distance)  # 输出: 8

# 将负数转换为正数
financial_data = [-100, 200, -300, 400]
positive_data = [abs(num) for num in financial_data]
print(positive_data)  # 输出: [100, 200, 300, 400]

# 二分查找算法中的应用
def binary_search(arr, target):
    left, right = 0, len(arr) - 1
    while left <= right:
        mid = (left + right) // 2
        if abs(arr[mid] - target) < 1e-6:  # 使用abs来判断浮点数的相等性
            return mid
        elif arr[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    return -1

arr = [1, 2, 3, 4, 5]
target = 3
result = binary_search(arr, target)
print(result)  # 输出: 2

# 复数的绝对值
complex_num = 3 + 4j
abs_value = abs(complex_num)
print(abs_value)  # 输出: 5.0

# 浮点数的近似相等判断
num1 = 0.1 + 0.2
num2 = 0.3
if abs(num1 - num2) < 1e-9:
    print("num1 and num2 are approximately equal")
else:
    print("num1 and num2 are not equal")

# 避免频繁调用abs函数
def process_data(data):
    result = []
    for num in data:
        if num < 0:
            result.append(-num)
        else:
            result.append(num)
    return result

data = [-1, 2, -3, 4]
processed_data = process_data(data)
print(processed_data)  # 输出: [1, 2, 3, 4]