i.cs.hku.hk/~yklam2/py
2018.5.29 Night.
Number base
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y = int(input("Input a year: "))
if (y%4 == 0 and y%100 != 0):
print("yes it is a leap year")
else:
if y%400 ==0:
print("yes it is a leap year")
else:
print("It is not leap year")
j = int(input("input a number: "))
while j>0 :
print(j%10)
j //=10
n = int(input("input a number: "))
t = [0,1]
for i in range(0,n-2):
t.append(t[i]+t[i+1])
print(t)
3. Data Structure
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month = int(input("Input a Month of a day: "))
first_day = int(input("Input a the first day is: "))
result = []
if (first_day ==0):
a = 1
result.append(a)
a=8
while (a < month):
result.append(a)
result.append(a+1)
a = a+7
else:
a = 7-first_day
while (a < month+6):
result.append(a)
result.append(a+1)
a = a+7
print(result)
#------------- Another Method-----------------------
month = int(input("Input a Month of a day: "))
first_day = int(input("Input a the first day is: "))
result = []
for i in range(month):
dow = (i + first_day) %7
if dow==6 or dow ==0:
result.append(i+1)
print(result)
Tuple
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a = int(input("Input a: "))
b = int(input("Input b: "))
while (b != 0):
a,b = b,a%b
print(a)
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b = 1
result = []
while (b != 0 ):
b = int(input("Input b: "))
if b == 0:
break
result.append(b)
print (result)
for i in range(1,(len(result)//2)+1):
print (result[i:-i])
#-------------[Method 2]
b = 1
result = []
while (b != 0 ):
b = int(input("Input b: "))
result.append(b)
for i in range(0,(len(result)//2)):
print (result[i:-(i+1)])
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s = input("Input string: ")
s = (s*2)
for i in range(0,len(s)//2):
if i==0:
print(s)
else:
print(" "*i + s[i:-i])
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s = input("Input string: ")
result = ""
for i in range (1,len(s)+1):
result = result + s[:i]
for i in range (1,len(s)+1):
result = result + s[i:]
print(result)
def myrange(a = "" ,b = "" ,c = "" ):
if(a=="" and b=="" and c==""):
print("no value is passing in")
if (a!="" and b!= "" and c!=""):
print ([a,b,c])
return [a,b,c]
if(a!="" and b!= ""):
print ([a,b])
return [a,b]
if(a!=""):
print([a])
return(a)
myrange()
myrange(1,2,3)
myrange(1,2)
myrange(1)
Chapter 5 Exercises 2
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import random
#Random Generate Methods
def randDot():
x = random.random()
y = random.random()
return (x*x + y*y <1)
#Find Pi
def findPi(n):
count = 0
for i in range(n):
if randDot():
count+=1
return 4 * count/n
print(findPi(1000000))
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Constructer
class Box:
def __init__(self, w, h, d):
self.w, self.h, self.d = w, h, d
def getVolume(self):
return self.w * self.h * self.d
b = Box(10, 20, 30)
print(b.getVolume())
c = b
b.w = 22
print(c.getVolume())
c.w = 66
print(b.getVolume())
'''
Results:
6000
13200
39600
39600
'''
Exercise of Class
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import math
class Frac:
_n = 1
_d = 1
def __init__(self,n,d):
self._n = n
self._d = d
def __str__(self):
self._simplify()
return f'{self._n:d}/{self._d:d}'
def _simplify(self):
gcd = math.gcd(self._n,self._d)
self._n //= gcd
self._d //= gcd
def invert(self):
return f'{self._n}/{self._d}'
f1 = Frac(2,4)
f2 = Frac(6,3)
print(f1,f2)
Other Exercises:
import math
class Frac:
_n = 1
_d = 1
def __init__(self,n,d):
self._n = n
self._d = d
def __str__(self):
self._simplify()
return f'{self._n:d}/{self._d:d}'
def _simplify(self):
gcd = math.gcd(self._n,self._d)
self._n //= gcd
self._d //= gcd
def invert(self):
self._d,self._n=self._n,self._d
def multi(self,f):
self._n *= f._n
self._d *= f._d
#Still has some problems, not simply add them together
def add(self,f):
self._n += f._n
self._d += f._d
def eval(self):
return self._n/self._d
x = Frac(1,3)
y = Frac(1,2)
x.add(x)
print(x)
x.add(y)
