# Python store value to RAM address on Ref table
# In Python, all data are object base.
x = 1
y = 1
print(id(x),id(y))
print(print(id(x),id(y))) #Next step print(None)
# Show up what variables are stored by dictionary.
print(globals())
del x
print(globals())
# Test assignment statement in Python. e.g. print(x=1) or print(del x)
x = 1; y = 1 ; print(print(id(x))) #Python accept ; to separate statements
# Python will accept expression with new lines
x = (1
+ 1
+1)
# \ is line contineouation, after that can't add comments
print(x)
x = 1 \
+1 \
+1
print(x)
x=1
if x==1 \
:
x=x+1
print(x)
#Python can add comment in expression
x = (1+ #comment
1 #comment
)
print(x)
# Python docstring
if x == 1 \
: #comment
pass
'''
docstring -
multiple
line comment
'''
x = x + 1
print(x)
help(print)
# When you not sure what is the content of function, you can us Pass statement to skip the error of indentation.
x = 1
if x == 1:
pass
y = 1
# _x is defined as private variable
from dio import *
#print(_x,y)
print(y)
a()
# __x is class variable
# __init__ is Python internal system variables
# List variables
ll = ["peter","ann","john","ryan"]
print(ll[0],ll[1],ll[2],ll[3])
ll[0]="anna" #List is mutable
print(ll)
# Tuple variable is immutable
tt= "peter","ann","john","ryan"
print(tt[0])
#tt[0]='dave' #TypeError, ' and " in python means the same, but not Java.
# Decomposition. Very handly if you have lots of assignments.
a,b = 1,2
print(a,b)
a,b,c = 1,2,3+2
print(a,b,c)
a,b = a+b, a+c
print(a,b,c)
a,b = (a,c),(c,a)
print(a,b,c)
a,b = [(a,c),(c,a)]
c,b=a # a,c
print(a,b,c)
# c+b,b+c = a,b #Return error because we can't assign value to an expression
b,b = a,c # b = a ; b = c = (a,c)
print(a,b,c)
# Fiboni
def fib(n):
a,b = 0,1
result = ()
for i in range(n):
result += (a,)
a,b = b, a+b
print(i)
return result
print(fib(10))
tt=1, #Create Tuple by , without , it's an integer
print(tt)
from tria import *
print(fib(10))
x = 1
print(type(fib),fib,type(x),id(x))
_x = 1
y = 2
def a():
print(_x)
# Why use _ to define for loop variable
def fib(n):
a,b = 0,1
result = ()
for _ in range(n):
result += (a,)
a,b = b, a+b
return result
