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We can check if a string is empty, contains only whitespace characters, or is NaN in Python using various methods:

• Checking for Empty String: Use the len() function to check the length of the string. Code

   

  Output: 

   

• Checking for Whitespace Characters: Use the isspace() method to check if the string contains only whitespace characters. Code

  

  Output: 

  

• Checking for NaN Value: There's no built-in concept of "NaN" for strings in Python like there is for numeric types. However, if we are dealing with NaN values as strings (e.g., if we have loaded data from a file or received it as input), we can simply check if the string is equal to "NaN". Code

   

  Output: 

   

• If we are dealing with a single string value and want to convert it to 0 if it’s either NaN or an empty string; otherwise, it returns the original value, then we can use the code:

  

  Output:

  

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Check if a string is empty or not (space is not considered as empty): Code:
           
       Output (The marked below are spaces):    
         

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Get definite an answer about string empty by removing spaces first: Code:
           
       Output (The marked below are spaces):    
         

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Check if a string is empty or space: Code:
           
       Output (The marked below are spaces):    
         

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Check if a string is in NaN value: Code:
           
       Output:    
         

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