datatype-list (en)

list is Python’s most common container. Wrapped in square brackets [], its items can be changed, can repeat, and keep their insertion order.

Create a list first, then loop through it with for.

my_list = [10, 20, 30, 40, 50]

for value in my_list:
    print(value)

output:

10
20
30
40
50

append() adds a new item to the end; prices[1] reads the second item by index (index starts at 0).

prices = [100, 102, 99]
prices.append(105)  # 加到結尾
print(prices[1])  # 102（index 1）

output:

102

pop(index): removes and returns the item at that index (defaults to the last one if omitted).

prices = [100, 102, 99, 105]
prices.pop(2)  # 移除 index 2 的 99，並回傳
print(prices)  # [100, 102, 105]

output:

[100, 102, 105]

remove(value): deletes the first item equal to value.

prices = [100, 102, 99, 105]
prices.remove(99)  # 刪掉第一個 99
print(prices)  # [100, 102, 105]

output:

[100, 102, 105]

del prices[index]: deletes by index, doesn’t return anything.

prices = [100, 102, 99]
del prices[0]  # 刪掉 100
print(prices)  # [102, 99]

output:

[102, 99]

Use sum() to add up and len() to count, to get the average.

race_times = [72.5, 74.2, 71.8, 73.1]
avg_time = sum(race_times) / len(race_times)
print(f"Average time: {avg_time:.1f}s")  # 72.9s

output:

Average time: 72.9s