There is no way in python natively to track all opened files. To do that you should either track all the files yourself or always use the with statement to open files which automatically closes the file as it goes out of scope or encounters an error.
with open('file.txt') as f: # do something with f here
You can also create a class to enclose all files and create a single close function to close all the files.
class OpenFiles(): def __init__(self): self.files =  def open(self, file_name): f = open(file_name) self.files.append(f) return f def close(self): list(map(lambda f: f.close(), self.files)) files = OpenFiles() # use open method foo = files.open("text.txt", "r") # close all files files.close()