this was a markdown cell and how a heading¶

sage is using python 3
good thing is that you can check line by line

2 + 2

4

type(234)

float

type(234.)

float

type(234.0)

float

type("hello world")

str

type('hello world')

str

101 - 2

99

9 / 3

  File "<ipython-input-10-00b7104e9bf2>", line 1
    9 / 3 // double slash for python 3
                        ^
SyntaxError: invalid syntax

51 //3

17

11*11

121

11**2

121

3^8

11

2^7

5

5%2

1

↑modulus

2. + 2.

4.0

2. + 2

4.0

float (any math) int = float

52. / 3

17.333333333333332

52. //3

17.0

"//" for integer, "/" for float

"hello" + "world"

'helloworld'

add string, just join them

"hello"*"world"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-23-1fea36b8cd73> in <module>()
----> 1 "hello"*"world"

TypeError: can't multiply sequence by non-int of type 'str'

"hello"/"world"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-24-fc98848b3340> in <module>()
----> 1 "hello"/"world"

TypeError: unsupported operand type(s) for /: 'str' and 'str'

"hello"**"world"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-25-df869e9c8fb4> in <module>()
----> 1 "hello"**"world"

TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'str'

"hello"%"world"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-26-5c5c2000917c> in <module>()
----> 1 "hello"%"world"

TypeError: not all arguments converted during string formatting

2 + "hello"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-27-282a54e01199> in <module>()
----> 1 2 + "hello"

TypeError: unsupported operand type(s) for +: 'int' and 'str'

2*"hello"

'hellohello'

because it's the same as "hello" +　"hello"

2.1*"hello"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-29-559775491960> in <module>()
----> 1 2.1*"hello"

TypeError: can't multiply sequence by non-int of type 'float'

SO FAR JUST ALL PYTHON, NOT ANY SAGE(mathematically stronger) YET

3*"hello"+"world"

'hellohellohelloworld'

"hello" + "" + "world"

'hellospace'

"hello" + " " + "world"

'hello world'

a = 3

b = 4

a = b

a+b

8

2 = 2

  File "<ipython-input-41-112056e27a6a>", line 1
    2 = 2
SyntaxError: can't assign to literal

2 == 2

True

type(a)

int

a = 0.2

type(a)

float

dynamically changing

a = "hello"

b = "world"

a+b

'helloworld'

type(2==3)

bool

2==3

False

2< 3

True

3 >= 2

True

"hello" != "hello "

True

4 != 5

True

for n in range(5):
    print(n)

  File "<ipython-input-57-a436cd77f76e>", line 1
    for n in range(5)
                     ^
SyntaxError: invalid syntax