Integer
Python doesn't like Java, C, or C++, it can handle any size of integer. Like 100
, -123
, 0
in decimal, octal, or hexadecimal.
example
//Code==========
print(-123)
print(0x12fd2)
//Result==========
-123
77778
Float
Python doesn't like Java, C, or C++, it doesn't care about double or float. Like 1.23
, 1.2e-20
, -3.5e7
example
//Code==========
print(1.2e-20)
print(-3.5e7)
//Result==========
1.2e-20
-35000000.0
String
Both ''
and ""
are working with string type, and allow using them by nested each other.
example
//Code==========
print("Hello World")
print('Hello Python')
//Result==========
Hello World
Hello Python
Escape character
Python also allow to print '
or "
, then you need to escape each charactor in use.
example
//Code==========
print("\'Hello\' \"World\"")
//Result==========
'Hello' "World"
\n
new line
\t
tab
\\
backslash
r
operator provides another way to make string escaping easier, wring as normal words within the r
statement
example
//Code==========
print(r'\(~_~)/ \(~_~)/')
//Result==========
\(~_~)/ \(~_~)/
Multi-line string
'''...'''
provides the way to writing a string in multiple lines, also can using comment to become multi-line comments
example(for markdown editor, code viewr doesn't support multi-line operator)
//Code==========
print r'''"To be, or not to be": that is the question.Whether it's nobler in the mind to suffer.'''
#'''"To be, or not to be": that is the question.Whether it's nobler in the mind to suffer.'''
//Result==========
"To be, or not to be": that is the question.Whether it's nobler in the mind to suffer.
Boolean
Python is Case Sensitive, there are only two value are valid for boolean type, True
and False
Logic Operators
it doesn't like other OOP languages, it uses and
, or
, and not
instead of using &&
, ||
, and !
example
//Code==========
print(100<99)
print((1<2) and (3<4))
//Result==========
False
True
Empty value
It uses None
, but in other OOP languages, they use null
Print statement
- in Python2, you can writing without parentheses, but in Python3 you have to use them, because in Python3,
print
is a function and no longer is a command - using
,
will generate a empty space
example
//Code==========
print('hello python')
print('hello', 'python')
//Result==========
hello python
hello python
Comment
using #
for line in Python is similar using //
in other OOP languages
example
//Code==========
#print('hello python')
//Result==========
Variable
Consider variable as a reference for the address of the data in memory
example
//Code==========
a = 'ABC'
b = a
a = 'XYZ'
print(b)
//Result==========
ABC
Unicode String
Generally, Unicode is using for international words. When using unicode, please add # -*- coding: utf-8 -*-
as the first line.
example
//Code==========
# -*- coding: utf-8 -*-
print('''我现在是有点儿饿了,你呢?''')
//Result==========
我现在是有点儿饿了,你呢?
Arithmetic
Same to other OOP languages, +
, -
, *
, /
, %
, ^
, etc. But in Python3, /
is special. /
in Python2 is dividing as integer, but in Python3, it will automatically switch integer to float, but if you still need dividing as integer, you need to use //
.
example
//Code==========
print(1/2)
print(1//2)
//Result==========
0.5
0