style: format code with Autopep8, Black, ClangFormat, dotnet-format, …

…Go fmt, Gofumpt, Google Java Format, isort, Ktlint, PHP CS Fixer, Prettier, RuboCop, Ruff Formatter, Rustfmt, Scalafmt, StandardJS, StandardRB, swift-format and Yapf

This commit fixes the style issues introduced in d4aab9f according to the output
from Autopep8, Black, ClangFormat, dotnet-format, Go fmt, Gofumpt, Google Java
Format, isort, Ktlint, PHP CS Fixer, Prettier, RuboCop, Ruff Formatter, Rustfmt,
Scalafmt, StandardJS, StandardRB, swift-format and Yapf.

Details: None

user_behavior_analysis/data_preparation.py

@@ -1,5 +1,6 @@
 import pandas as pd
 
+
 class DataPreparation:
     def __init__(self, data_file):
         self.data_file = data_file