Discord.py, send a message to a channel I just created
Solution 1:
You're not using the result of the channel creation, instead you're using i which is your index in the iteration. As described in the documentation, create_text_channel returns a TextChannel object, try using that instead:
for i in range (10):
channel = await guild.create_text_channel('test channel')
for j in range (5):
await channel.send("ah")