列表是能够容纳不同类型项的强大工具。在 Python 编程语言中，我们有各种列表函数或方法，可以用于添加、删除、排序和反转项。
在本节中，我们将通过每个示例向您解释可用的列表函数。我们还将包含一些常见的列表方法，如 sum、min 和 max 函数。
Python 列表函数
Python 列表数据类型有单独的函数或方法用于添加、删除、查找、操作和反转元素。请使用这些链接通过示例来理解列表函数。
以下是可用的列表方法或函数。
| 函数 | 描述 |
|---|---|
| append() | 它将项 x 追加或添加到列表的末尾。 |
| insert() | 在索引位置 i 处插入指定的项 x。 |
| extend() | 它将新列表添加到现有列表的末尾。 |
| del | 此函数删除指定索引处的值。 |
| pop() | 删除指定索引处的项并显示被删除的项。删除后，其余项向前移动以填充索引间隙。 |
| remove() | 它删除用户指定的项。如果我们知道该项，这将非常有用。 |
| copy() | 这将浅拷贝项到一个新的列表中。 |
| clear() | 它清除现有的元素。 |
| count() | 计算值在列表中重复的次数。 |
| reverse() | 此方法反转列表项。 |
| sort() | 按升序对项进行排序。 |
| index() | index 方法打印指定值的索引位置。 |
Python 列表函数示例
以下是可用的列表函数示例。
list append 方法
append 帮助我们在末尾添加项。此示例将 520、650 和 -70 添加到数字列表中。
number = [150, 200, 130, 340]
print("Original Items are : ", number)
number.append(520)
print("After 520 appended are : ", number)
number.append(650)
print("After 650 appended are : ", number)
number.append(-70)
print("After -70 appended are : ", number)
Original Items are : [150, 200, 130, 340]
After 520 appended are : [150, 200, 130, 340, 520]
After 650 appended are : [150, 200, 130, 340, 520, 650]
After -70 appended are : [150, 200, 130, 340, 520, 650, -70]list extend 函数
extend 函数将新列表的项添加到现有列表的末尾。在此示例中，我们声明了数字 a、b 和 c。接下来，我们使用此函数将 a、b 和 c 项添加到 numbers 列表中。
number1 = [10, 200, 630, 90]
print("Original Items are : ", number1)
a = [222, 333]
number1.extend(a)
print("After extending to a : ", number1)
b = [5, 9]
number1.extend(b)
print("After extending to b : ", number1)
c = [-12, 73]
number1.extend(c)
print("After extending to c : ", number1)
Original Items are : [10, 200, 630, 90]
After extending to a : [10, 200, 630, 90, 222, 333]
After extending to b : [10, 200, 630, 90, 222, 333, 5, 9]
After extending to c : [10, 200, 630, 90, 222, 333, 5, 9, -12, 73]insert
Python insert 函数或方法将给定的列表项插入到指定的索引位置。第一个语句在索引位置 2 处插入 100，第二个语句在位置 4 处插入 500。
number2 = [5, 10, 15, 22, 19, 90]
print("Original Items are : ", number2)
number2.insert(2, 100)
print("After Inserting 100 at 2 : ", number2)
number2.insert(4, 500)
print("After Inserting 500 at 4 : ", number2)
number2.insert(8, 700)
print("After Inserting 700 at 8 : ", number2)
Original Items are : [5, 10, 15, 22, 19, 90]
After Inserting 100 at 2 : [5, 10, 100, 15, 22, 19, 90]
After Inserting 500 at 4 : [5, 10, 100, 15, 500, 22, 19, 90]
After Inserting 700 at 8 : [5, 10, 100, 15, 500, 22, 19, 90, 700]list del 函数
del 函数或方法删除指定索引处的项。此示例删除索引位置 5、0 和 3 处的项。
number3 = [9, 17, 10, 18, 55, 120, 90]
print("Original Items are : ", number3)
del number3[5]
print("After Deleting Item at Index 5 : ", number3)
del number3[0]
print("After Deleting Item at Index 0 : ", number3)
del number3[3]
print("After Deleting Item at Index 3 : ", number3)
Original Items are : [9, 17, 10, 18, 55, 120, 90]
After Deleting Item at Index 5 : [9, 17, 10, 18, 55, 90]
After Deleting Item at Index 0 : [17, 10, 18, 55, 90]
After Deleting Item at Index 3 : [17, 10, 18, 90]Python list pop 函数
pop 删除用户给定的索引处的列表项并显示被删除的元素。删除后，剩余的值会调整以填充索引间隙。下面的程序删除并显示索引位置 6、0 和 4 处的项。
number4 = [17, 6, 10, 18, 120, 220, 90, 119]
print("Original Items are : ", number4)
a = number4.pop(6)
print("After Deleting Item at Index 6 : ", number4)
print("Items Extracted by the Pop Function : ", a)
b = number4.pop(0)
print("\nAfter Deleting Item at Index 0 : ", number4)
print("Items Extracted by the Pop Function : ", b)
c = number4.pop(4)
print("\nAfter Deleting Item at Index 4 : ", number4)
print("Items Extracted by the Pop Function : ", c)
Original Items are : [17, 6, 10, 18, 120, 220, 90, 119]
After Deleting Item at Index 6 : [17, 6, 10, 18, 120, 220, 119]
Items Extracted by the Pop Function : 90
After Deleting Item at Index 0 : [6, 10, 18, 120, 220, 119]
Items Extracted by the Pop Function : 17
After Deleting Item at Index 4 : [6, 10, 18, 120, 119]
Items Extracted by the Pop Function : 220List remove 函数
如果我们知道要删除的项，我们可以使用 remove 函数来删除该数字。下面的程序删除数字项 22、19 和 5。
number5 = [55, 98, 10, 18, 22, 162, 170, 90]
print("Original Items are : ", number5)
number5.remove(22)
print("After Removing 22 are : ", number5)
number5.remove(98)
print("After Removing 98 are : ", number5)
number5.remove(162)
print("After Removing 162 are : ", number5)
Original Items are : [55, 98, 10, 18, 22, 162, 170, 90]
After Removing 22 are : [55, 98, 10, 18, 162, 170, 90]
After Removing 98 are : [55, 10, 18, 162, 170, 90]
After Removing 162 are : [55, 10, 18, 170, 90]list copy
copy 函数将项浅拷贝到一个全新的列表中。
numbers6 = [6, 10, 18, 220, 90, 119]
print("Items are : ", numbers6)
newNum = numbers6.copy()
print("\nNew Items are : ", newNum)
Items are : [6, 10, 18, 220, 90, 119]
New Items are : [6, 10, 18, 220, 90, 119]List clear
clear 函数可帮助您清除所有现有项。执行此函数后，如果您调用或打印相同的列表，它将返回一个空列表。
numbers7 = [6, 10, 18, 220, 90, 119]
print("Items are : ", numbers7)
new = numbers7.clear()
print("\nNew Items are : ", new)
Items are : [6, 10, 18, 220, 90, 119]
New Items are : None如何计算列表中的项？
List count 函数计算指定值重复的次数。在这里，我们计算 22、6 和 19 重复了多少次。
numbers8 = [22, 6, 15, 19, 22, 90, 19, 22, 6, 19, 22]
print(numbers8)
a = numbers8.count(22)
print("Number of Times 22 was repeated : ", a)
b = numbers8.count(6)
print("Number of Times 6 was repeated : ", b)
c = numbers8.count(19)
print("Number of Times 19 was repeated : ", c)
[22, 6, 15, 19, 22, 90, 19, 22, 6, 19, 22]
Number of Times 22 was repeated : 4
Number of Times 6 was repeated : 2
Number of Times 19 was repeated : 3list index
List index 方法返回用户给定值的索引位置。在这里，我们在 numbers 列表中查找项 12、-9 和 -19 的索引位置。
numbers = [22, 6, 12, 15, 19, 16, -9, 4]
print("Items are : ", numbers)
a = numbers.index(12)
print("Index Position of 12 : ", a)
b = numbers.index(-9)
print("Index Position of -9 : ", b)
c = numbers.index(19)
print("Index Position of 19 : ", c)
Items are : [22, 6, 12, 15, 19, 16, -9, 4]
Index Position of 12 : 2
Index Position of -9 : 6
Index Position of 19 : 4如何反转列表项？
List reverse 方法有助于反转列表项。此代码反转 numbers 列表。
numbers = [22, 6, 12, 15, 19, 16, -9, 4]
print("Items are : ", numbers)
numbers.reverse()
print("\nNew Items are : ", numbers)
Items are : [22, 6, 12, 15, 19, 16, -9, 4]
New Items are : [4, -9, 16, 19, 15, 12, 6, 22]sort list items
sort 方法按升序对列表项进行排序。
numb = [2, 6, 0, 12, 15, -2, 19, 16, -9, 4]
print(numb)
numb.sort()
print("\nSorted : ", numb)
[2, 6, 0, 12, 15, -2, 19, 16, -9, 4]
Sorted : [-9, -2, 0, 2, 4, 6, 12, 15, 16, 19]此示例显示列表方法 sum、min 和 max。sum 返回给定列表中所有项的总和。接下来，min 返回给定项中的最小值，max 返回最大值。
numbers = [2, 6, 17, 12, 15, -2, 25, 16, -9, 4]
print("Items are : ", numbers)
# Max
maximum = max(numbers)
print("The Maximum Value in this : ", maximum)
# Min
minimum = min(numbers)
print("The Minimum Value in this : ", minimum)
# Sum
total = sum(numbers)
print("The Sum of all Value in this : ", total)
