There are several libraries that can be used to extract tables from PDFs and convert them into pandas DataFrames in Python. Some options include:

1. pdfplumber: This is a lightweight library that allows you to extract tables from PDFs and convert them into pandas DataFrames. To use it, you will need to install it first using pip install pdfplumber. Here is an example of how to extract a table from a PDF and convert it into a DataFrame using pdfplumber:

    import pdfplumber
    import pandas as pd
   
    # Open the PDF file using pdfplumber
    with pdfplumber.open("sample.pdf") as pdf:
        # Iterate through all the pages in the PDF
        for page in pdf.pages:
            # Extract the table from the page
            table = page.extract_table()
            # Convert the table into a pandas DataFrame
            df = pd.DataFrame(table[1:], columns=table[0])
            # Print the DataFrame
            print(df)
   

2. camelot: This is another library that can be used to extract tables from PDFs and convert them into pandas DataFrames. To use it, you will need to install it first using pip install camelot-py[cv]. Here is an example of how to extract a table from a PDF and convert it into a DataFrame using camelot:

    import camelot
    import pandas as pd
   
    # Extract the tables from the PDF using camelot
    tables = camelot.read_pdf("sample.pdf")
   
    # Iterate through the tables and convert each one into a DataFrame
    for table in tables:
        df = table.df
        # Print the DataFrame
        print(df)
   

3. tabula-py: This is another library that can be used to extract tables from PDFs and convert them into pandas DataFrames. To use it, you will need to install it first using pip install tabula-py. Here is an example of how to extract a table from a PDF and convert it into a DataFrame using tabula-py:

    import tabula
    import pandas as pd
   
    # Read the PDF into a pandas DataFrame using tabula-py
    df = tabula.read_pdf("sample.pdf", pages="all")
   
    # Print the DataFrame
    print(df)
   

   These are just a few examples of the libraries and techniques that can be used to extract tables from PDFs and convert them into pandas DataFrames in Python. You may need to experiment with different libraries and techniques to find the one that works best for your specific use case.