1. It is different from "4 space" and "1 tab" in the python!!!
2. Use the commend "a in b" is a True of False commend. We use it to justice whether element "A" is in list "B"
Dictionarys:
1. Compare to list. The advantages of dictionary is that it is easier to find the right value which is corresponse to certain index or other value.
2. In the dictionary,we use {} curly brackets to define a dictionary.
3. In the dictionary, we use [] to add elements or search the dictionary.
Function:
1. return function have to be in the bracket ().
2. return makes the function more stable, and it always returns some variables which is not defined outside the function.
3. For some parameters, if the default value is True, so while calling the function, we do not need to write them down to make them True.
