如何检查列表项是否在另一个列表中

Question

我正在尝试比较两个列表（预期列表和实际列表）。 我想检查实际的列表项中是否存在预期的列表项。 我正在尝试以下示例代码。 我可以尝试set(expected)-set(actual) 。这将给我带来不同，但我想检查是否存在项目，否则显示哪个项目不存在。有人可以指导我，如何实现低于预期的结果或我犯了什么错误在做。 如果我是学习者，请忽略是否有错误。

actual = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log', 'sampleresources.csv']
    expected = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log']
    for i in expected:
        for b in actual:
            if b.split(".")[0] in i:
                print "{} is present".format(b)
            else:
                print "{} is not present".format(i)

实际结果：

resources.sh is present
resources.sh is not present
resources.csv is present
resources.log is present
resources.sh is not present
server.properties is not present
server.properties is present
server.properties is not present
server.properties is not present
server.properties is not present
resources.sh is present
resources.csv is not present
resources.csv is present
resources.log is present
resources.csv is not present
resources.sh is present
resources.log is not present
resources.csv is present
resources.log is present
resources.log is not present

预期结果：

resources.sh is present
server.properties is present
resources.csv is present 
resources.log is present 
sampleresources.csv is not present

Answer 1

您可以只遍历actual一次：

for i in actual:
     if i in expected:
         print(i, "is present")
     else:
         print(i, "is not present")

输出：

resources.sh is present
server.properties is present
resources.csv is present
resources.log is present
sampleresources.csv is not present

Answer 2

actual = ['resources.sh', 'server.properties', 'resources.csv','resources.log', 'sampleresources.csv']
expected = ['resources.sh', 'server.properties', 'resources.csv',  'resources.log']
for i in actual:
    if i in expected:print "{} is present".format(i)
    else:print "{} is not present".format(i)

输出：

resources.sh is present
server.properties is present
resources.csv is present
resources.log is present
sampleresources.csv is not present

Answer 3

[print ("{} is present".format(b)) if b in expected  
else print("{} is not present".format(b)) for b in actual]

Answer 4

actual = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log', 'sampleresources.csv']
expected = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log']

result = [elem + ' is present' if elem in expected else elem + ' is not present' for elem in actual]
print result

Answer 5

您可以使用列表理解来获得更简洁的代码：

  actual = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log', 'sampleresources.csv']
  expected = ['resources.sh', 'server.properties', 'resources.csv', 'resources.log']

  def print_msg(x):
      print(x,'is present')

  [print_msg(b) for i in actual for b in expected if i == b]