AttributeError: module 'pymysql' has no attribute 'escape_string'

This error occurs when you try to use the `escape_string` function of the `pymysql` module, but the function does not exist in the module.

The `escape_string` function is used to escape special characters in a string before it is used in a SQL query, to prevent SQL injection attacks.

To fix this error, you can try using the `escape` function instead, which is a similar function provided by the `pymysql` module for escaping strings.

Here's an example of how you can use the `escape` function:

import pymysql

# establish a database connection
conn = pymysql.connect(host='localhost', user='root', password='password', db='mydb')

# create a cursor object
cursor = conn.cursor()

# define a string with special characters
my_string = "John'; DROP TABLE users; --"

# escape the string before using it in a SQL query
escaped_string = pymysql.escape(my_string)

# execute a SQL query using the escaped string
query = f"SELECT * FROM users WHERE name='{escaped_string}'"
cursor.execute(query)

# fetch the results and print them
results = cursor.fetchall()
print(results)

# close the database connection
conn.close()