Ravenclaw has a reputation as the most intellectual Hogwarts house, so we can assume that a Ravenclaw would naturally be attracted to similarly sharp minds. It would seem, then, that Ravenclaws are more suited to other Ravenclaws - and sometimes Slytherins.
Slytherins and Ravenclaws have a great time bouncing ideas back and forth. While they might not be the best of friends, the Ravenclaws — being admittedly more intellectually advanced — understand how wild our minds can run and are able to empathize and provide a sense of rationality.
ENEMIES. Slytherins and Ravenclaws - Slytherins hate rules and Ravenclaws are ingenious. Together they can take over the world or create amazing spells. Or they can hate eachother with a fury and rage.
Ravenclaw House appeared to have little rivalry with the other houses, except in Quidditch. Harry Potter believed that they tended to side with Gryffindor in its rivalry with Slytherin, as did Hufflepuff house.
Traits. Ravenclaws possess the traits of cleverness, wisdom, wit, intellectual ability and creativity. According to Slytherin prefect Gemma Farley, Ravenclaws are so competitive when it comes to academic success that they are known to back stab each other, and likely other students, in order to get top marks.
One example is creativity. For Ravenclaws, finding creative out of scenarios was second nature to them, but Hermione relied on procedures and rules to guide her when she was lost. She also has a drive to be the best, which Ravenclaws aren't known for.
Ravenclaws. In planning, there are two dichotomies among the four Houses: Gryffindor/Ravenclaw and Hufflepuff/Slytherin. Ravenclaws are the opposite of Gryffindors when making plans; they will figure out every little detail.
While it is not clear if there is a similar rivalry between Ravenclaw and Hufflepuff, it seems fairly unlikely due to the cheerful disposition of the Heads for said Houses, as opposed to the contempt of Professor Snape and the passion of Professor McGonagall.
In a lot of ways, it makes them unlikeable when they come across those who are outside of their house. Ravenclaws believe they are right in most situations and don't enjoy finding themselves to be otherwise.
Ravenclaws can value intellectualism above all else, which means they can neglect caring for other people. They may even betray people to be more successful or powerful. They can also be arrogant because they are too busy philosophizing and examining theories to empathize and experience life.
After Helena was tragically killed, legend tells us that Rowena Ravenclaw died of a broken heart. No wonder Helena's ghost, which became Ravenclaw's house ghost, often roams the corridors in silence.
Gryffindor may have a "loud" energy while Ravenclaw has a "quiet" energy, but both of these people have magnetic, engaging personalities. When they're together, this couple is the life of the party. It will be easy to keep the romance alive with captivating conversation and exciting new adventures.
Not only is it canon that no Slytherins fought, Voldemort mentions that all (or at least many) Slytherins joined him outright. He says, "If your son is dead, Lucius, it is not my fault. He did not come and join me, like the rest of the Slytherins." Pretty awkward.
Ravenclaw, the "smart House," values learning, wisdom, wit, and intellect. Students are academically motivated and creative thinkers. Ravenclaws can be eccentric and curious, always seeking to learn more. They are logical and rational, but also think outside the box.
The characters Godric Gryffindor and Salazar Slytherin, along with Helga Hufflepuff and Rowena Ravenclaw, founded Hogwarts over a thousand years ago. Because of their disagreement over pure-blood and Muggle-born students, Gryffindor, Slytherin and their respective houses at Hogwarts became rivals.
Harry then threw the Patronus charm at them and then managed to win the snitch, winning the game for Gryffindor. Gryffindor were delighted by the win, cheering and running onto the pitch. The team were treated to a party by their house which made them feel they had already won the cup.
Padma Patil is Parvati's twin sister. It's unknown how close the two girls are. It can be assumed that they are very close, as is the case with most twins. The girls were separated once they began attending Hogwarts, as Parvati was sorted into Gryffindor and Padma into Ravenclaw.
Finally, Slytherin is thought of as the 'evil' house. These stereotypes are found throughout Harry Potter, with Harry himself refusing to be sorted into Slytherin and Draco Malfoy saying he'd leave if he were sorted into Hufflepuff.
While Slytherin historically dominates the House competition, in the books, Gryffindor wins at the last second (often from Dumbledore's help, but that's beside the point). That's the lesson in the books: Gryffindor wins in a literal and metaphorical way. They're competitive, but not to the point of being mean-spirited.
Draco Malfoy was sorted into Slytherin House at Hogwarts School of Witchcraft and Wizardry. This was in line with his family's strong belief in the importance of blood purity, a characteristic trait of Slytherin house.
He actually asked the Sorting Hat to place him in Hufflepuff, as he was intimidated by Gryffindor's reputation for bravery, but the Sorting Hat didn't agree. They debated it for so long, that he was close to being what is known as a Hatstall, which is a term for any student whose Sorting takes longer than five minutes.
Simple: None of the main characters are in them. The books have as much space and time as they need. The movies are short and every second counts. Ravenclaw and Hufflepuff exist in the movies just to be accurate to the books and replicate the same world building.
