Here’s a tip on how to memorize something without going insane: Do a tiny bit at a time throughout the day and mark down what you need to work on most. Do not try to sit down for two hours straight and memorize these tables. This won’t work. Your brain will really only retain whatever you studied in the first 15 or 30 minutes anyway.
Tuple
Tuple 是不可变的 list。一旦创建了一个 tuple，就不能以任何方式改变它。
What does result = sentence[:] do? That’s a Python way of copying a list. a = b # 只是copy引用 a = b[:] # clone 复制新对象
class Employee(Person):
def __init__(self, name, salary):
## hmm what is this strange magic?
super(Employee, self).__init__(name)
##
self.salary = salary
Python 关键字大小写注意
- object
- None
os.environ
import os
path = os.environ["PATH"]
user = os.environ["USER"]
editor = os.environ["EDITOR"]
... etc ...
Modifications to os.environ affect both the running program and subprocesses created by Python.
sys.path
import sys sys.path.append("mymodules.zip") import foo, bar