Python3 Data Type _1

Coding

By default, Python 3 source files are encoded in UTF-8, and all strings are Unicode strings. Of course you can also specify a different encoding for the source file:

1 #_*_ coding:utf-8 _*

In Python3, non--ascii identifiers are also allowed.

Comments

Single-line comments in Python are denoted by "#", multiline comments with three single quotes or three double quotation marks " or" "

1(" ")2 Luckynum = 63 For I in range (3):4 input_num = Int (input (' Please enter the number you want to guess: ') ')5 if Input_num > Luckynum:6 print (' The number you entered is too big! ')7 elif Input_num < luckynum:8 print (' The number you entered is too small! ')9 Else:Ten print (' Congratulations on your TM's guess! ') One  Break A Else: - print ("wrong guessing more than three times ~") - (" ") the  - #name = input (' Please enter your name: ')

Line and indent

Python is indented to represent blocks of code, and the same code block is indented in a consistent format, usually in the form of four spaces.

Data types and variables for Python

Data types in Python: integer (int), floating-point (float), Boolean (bool), character (string), null (None)

Integer

For example, 1, exactly the same as a mathematical integer.

Floating point number

For example, 0.11, a floating-point number is a decimal. Integers and floating-point numbers are stored internally in different ways, and integer operations are always accurate (is division accurate?), and floating-point arithmetic can have rounding errors.

Boolean type

Boolean type only True and False two values, for example

>>> 3>2True>>> 3>4False

Boolean values can be evaluated with and, or, not

The and operation is true with the result that only all of the results are true (true):

1  and True 2 True 3  and False 4 False 5  and False 6 False

An OR operation is an operation, as long as one of the true,or operation results is true;

1 or True 2 True 3 or False 4 True 5 or False 6 False 7

The not operation is a non-operation, and he is a monocular operator that turns true into False,false true:

1  not True 2 False 3  not False 4 True 5

Boolean values are often used in conditional judgments, such as

If age >= 18:print ' adult ' else:print ' teenager ' null null value is a special value in Python, denoted by none. None cannot be understood as 0, because 0 is meaningful, and none is a special null value.

Character type

Refers to the string

strings are enclosed in "or" " Strings!" What if the inside of a string contains both ' and contains '? You can use the escape character \ To identify, such as want to print I ' M "OK"!

>>> print (' i\ ' m \ "ok\"! ') I ' m "OK"!

The escape character \ can escape many characters, such as \ n for a newline character, \t for a tab, and the character \ itself to be escaped, so the character represented by \ \ is \, Try it in the interactive environment

 1  >>> print  ( '     )  "  m learning  3  python.  4  >>> print  ( '  

If there are many characters in the string that need to be escaped, it is impossible to add a lot of \, in order to simplify, Python runs with R ' ' means that the string inside of ' is not escaped by default

1 Print ('\\\t\\') 2 \     3 Print (R'\\\t\\') 4 \\\t\\

If there is a lot of line wrapping in the string, it is not good to read in a line, in order to simplify the use of "..." This means multiple lines of content

>>> print (' Q1 Q2 Q3 Q4 Q5 ') Q1 Q2 Q3 Q4 q5>>>

Python3 Data Type _1