+ + Output insist on thinking
1, learning: View provides video (30 minutes) + self-organize notes (2 hours) + video output weekend
2, organize notes by way of questioning.
How to tell if a value is not a string: use type (variable names)
After the identity of the query is what type of statement can be used to determine if a character stitching, an int is mathematical operations like addition and subtraction
Determining a data type is not str or int the like, may be the identity operator is is not
>>> type(name) is int
True
>>> type(name) is str
False
>>>
>>> type(name) is not str
True
>>> type(name) is not int
False
None: represents the empty
General application scenarios: for example, you store a variable used when no initial value, if the initial value if the variable is not so directly on the error.
Such as playing games, you have to initialize a girlfriend, you need to fill in your name, age, height, weight and other information, which is to allow players to fill in, fill in before, you have to put a good definition of variables, it would have to save a value this value 0,1 to placeholder inappropriate use True, False is also inappropriate, the most appropriate use None
1, learning: View provides video (30 minutes) + self-organize notes (2 hours) + video output weekend
2, organize notes by way of questioning.
How to tell if a value is not a string: use type (variable names)
After the identity of the query is what type of statement can be used to determine if a character stitching, an int is mathematical operations like addition and subtraction
Determining a data type is not str or int the like, may be the identity operator is is not
>>> type(name) is int
True
>>> type(name) is str
False
>>>
>>> type(name) is not str
True
>>> type(name) is not int
False
None: represents the empty
General application scenarios: for example, you store a variable used when no initial value, if the initial value if the variable is not so directly on the error.
Such as playing games, you have to initialize a girlfriend, you need to fill in your name, age, height, weight and other information, which is to allow players to fill in, fill in before, you have to put a good definition of variables, it would have to save a value this value 0,1 to placeholder inappropriate use True, False is also inappropriate, the most appropriate use None