使用Python检查目录是否包含文件

在Python中查找目录是否为空可以使用os库的listdir()方法来实现。 Python中的 OS 模块提供了与操作系统交互的功能。该模块提供了一种使用操作系统相关功能的可移植方式。

Syntax: os.listdir()

Returns: A list of files present in the directory, empty list if the directory is empty

现在通过调用listdir()方法，我们可以获得目录中所有文件的列表。要检查目录的空性，我们应该检查返回列表的空性。我们有很多方法可以做到这一点，让我们一一检查。

1. 通过将返回的列表与硬编码的空列表进行比较
   空列表可以写为[] 。所以我们可以将返回列表的相等性与[]进行比较。

   # Python program to check
   # if a directory contains file
     
     
   import os
     
   # path of the directory
   directoryPath = "D:/Pycharm projects/GeeksforGeeks/Nikhil"
     
   # Comparing the returned list to empty list
   if os.listdir(directoryPath) == []:
           print("No files found in the directory.")
       else:
           print("Some files found in the directory.")
   

   输出：

   Some files found in the directory.
   

2. 通过将返回列表的长度与 0 进行比较
   我们可以使用Python的len()方法获取列表的长度。如果返回列表的长度为零，则目录为空，否则为空。

   # Python program to check if
   # a directory contains file
     
     
   import os
     
   # path of the directory
   directoryPath = "D:/Pycharm projects/GeeksforGeeks/Nikhil"
     
   # Checking the length of list
   if len(os.listdir(directoryPath)) == 0:
           print("No files found in the directory.")
       else:
           print("Some files found in the directory.")
   

   输出：

   Some files found in the directory.
   

3. 通过比较列表的布尔值
   在上述方法中，我们使用了列表长度的显式比较。现在我们正以一种更 Pythonic 的方式使用真值测试。空列表在Python中被评估为 False。

   # Python program to check if
   # a directory is empty
     
     
   import os
     
   # path of the directory
   directoryPath = "D:/Pycharm projects/GeeksforGeeks/Nikhil"
     
   # Checking the boolean value of list
   if not os.listdir(directoryPath):
           print("No files found in the directory.")
       else:
           print("Some files found in the directory.")
   

   输出：

   Some files found in the directory.
   

完整的源代码：

# Python program to check if
# the directory is empty
  
import os
  
  
# Function for checking if the directory
# containes file or not
def isEmpty(directoryPath):
  
    # Checking if the directory exists or not
    if os.path.exists(directoryPath):
  
        # Checking if the directory is empty or not
        if len(os.listdir(directoryPath)) == 0:
            return "No files found in the directory."
        else:
            return "Some files found in the directory."
    else:
        return  "Directory does not exist !"
  
# Driver's code
  
# Valid directory
directoryPath = "D:/Pycharm projects/GeeksforGeeks/Nikhil"
print("Valid path:", isEmpty(directoryPath))
  
# Invalid directory
directoryPath = "D:/Pycharm projects/GeeksforGeeks/Nikhil/GeeksforGeeks"
print("Invalid path:", isEmpty(directoryPath))

输出：

Valid path: Some files found in the directory.
Invalid path: Directory does not exist !