planets.index('Pluto') --- ValueError Traceback (most recent call last) /tmp/ipykernel_19/2263615293.py in <module> ---> 1 planets.index('Pluto') ValueError: 'Pluto' is not in list Oh,我们删掉了。 为了确定变量是否在列表中,我们可以使用in: 输入: # Is Earth a planet? "Earth" in...
# Python 程序演示向列表中添加元素# 创建一个列表List= []print("初始空列表: ")print(List)# 向列表中添加元素List.append(1)List.append(2)List.append(4)print("\n添加三个元素后的列表: ")print(List)# 使用迭代器向列表中添加元素foriinrange(1,4):List.append(i)print("\n从 1 到 3 添加...
You can access individual elements in a list or tuple using the item’s index in square brackets. This is exactly analogous to accessing individual characters in a string. List indexing is zero-based, as it is with strings.Consider the following list:...
To access elements of a list in Python, use variable name followed by square brackets, and the index inside the square brackets. An example is provided below. </> Copy element = aList[index] We already know that index starts from0. Therefore,aList[0]fetches first element of the list an...
Python list slice step The third index in a slice syntax is the step. It allows us to take every n-th value from a list. main.py #!/usr/bin/python vals = [-2, -1, 0, 1, 2, 3, 4, 5, 6] print(vals[1:9:2]) print(vals[::2]) print(vals[::1]) print(vals[1::3]...
Lists#列表 Lists are another type of object in Python. They are used to store an indexed list of items.A list is created using square brackets with commas separating items.The certain item in the list can be accessed by using its index in square bracke
We canchange which item is at a particular indexbyassigningto that index: >>>colors[0]="pink">>>colors['pink', 'green', 'blue', 'yellow'] Lists also supportnegative indexing. Index-1gives us the last item in a list,-2gives the second to last, and so on: ...
/usr/bin/python list1 = ['physics', 'chemistry', 1997, 2000]; print list1; del list1[2]; print "After deleting value at index 2 : " print list1; 以上实例输出结果: ['physics', 'chemistry', 1997, 2000] After deleting value at index 2 :...
insert(index: int, x: object):None Inserts an element x at a given index. Note that the first element in the list has index 0 and returns None. remove(x:object):None Removes the first occurrence of element x from the list and returns None reverse():None Reverse the list and returns...
print(index,name) for index,pyl in enumerate("python"): print(index,pyl) 0 p 1 y 2 t 3 h 4 o 5 n family =["lsf","zyy","yx","lyf","zsf","ljz",6,8,33] for index , familyname in enumerate(family): print(index+1,familyname) ...