Which artist was post-Impressionist and often painted scenes in nightclubs and theaters?

The artist you're referring to is Toulouse-Lautrec. He was a post-Impressionist painter known for his vibrant depictions of Parisian nightlife, particularly scenes in nightclubs and theaters. His works often featured the bohemian lifestyle of the late 19th century, capturing the energy and atmosphere of the venues he frequented. Toulouse-Lautrec's distinctive style and use of color made him a key figure in the art world during that era.