Python|将第二个列表中的元素替换为第一个列表中相同元素的索引

给定两个字符串列表，其中第一个列表包含第二个列表的所有元素，任务是将第二个列表中的每个元素替换为第一个列表中元素的索引。
方法#1：使用迭代

Python3

# Python code to replace every element
# in second list with index of first element.
 
# List Initialization
Input1 = ['cut', 'god', 'pass']
Input2 = ['god', 'cut', 'cut', 'cut',
          'god', 'pass', 'cut', 'pass']
 
# List Initialization
Output = []
 
# Using iteration
for x in Input2:
    for y in Input1:
        if x == y:
            Output.append(Input1.index(y))
 
# Printing output
print("initial 2 list are")
print(Input1, "\n", Input2)
print("Second list after replacement is:", Output)

输出：

initial 2 list are
['cut', 'god', 'pass'] 
 ['god', 'cut', 'cut', 'cut', 'god', 'pass', 'cut', 'pass']
Second list after replacement is: [1, 0, 0, 0, 1, 2, 0, 2]

方法#2：使用列表推导

Python3

# Python code to replace every element
# in second list with index of first element.
 
# List initialization
Input1 = ['cut', 'god', 'pass']
 
# using enumerate
temp = {y:x for x, y in enumerate(Input1)}
 
# List initialization
Input2 = ['god', 'cut', 'cut', 'cut',
          'god', 'pass', 'cut', 'pass']
 
# Using list comprehension
Output = [temp.get(elem) for elem in Input2]
 
# Printing output
print("initial 2 list are")
print(Input1, "\n", Input2)
print("Second list after replacement is:", Output)

输出：

initial 2 list are
['cut', 'god', 'pass'] 
 ['god', 'cut', 'cut', 'cut', 'god', 'pass', 'cut', 'pass']
Second list after replacement is: [1, 0, 0, 0, 1, 2, 0, 2]

方法#3：使用地图

Python3

# Python code to replace every element
# in second list with index of first element.
 
# List initialization
Input1 = ['cut', 'god', 'pass']
 
# List initialization
Input2 = ['god', 'cut', 'cut', 'cut',
          'god', 'pass', 'cut', 'pass']
 
elem = {k: i for i, k in enumerate(Input1)}
Output = list(map(elem.get, Input2))
 
# Printing output
print("initial 2 list are")
print(Input1, "\n", Input2)
print("Second list after replacement is:", Output)

输出：

initial 2 list are
['cut', 'god', 'pass'] 
 ['god', 'cut', 'cut', 'cut', 'god', 'pass', 'cut', 'pass']
Second list after replacement is: [1, 0, 0, 0, 1, 2, 0, 2]