List files in a directory

os.listdir(path)

List files recursively

os.walk(path)

Read YAML file

with open("data.yaml", 'r') as stream:
	data_loaded = yaml.load(stream)

ipython autoreload

%load_ext autoreload
%autoreload 2

File exists

os.path.exists(path)
os.path.isdir(path)

Write to file

with open("demofile2.txt", "w+") as f:
	f.write("Now the file has more content!")