002-3. Iteration statement focusing on "for" with randomly generated numbers
<![CDATA[
@
# I use random module
import random
# starting, ending, inc and dec
print(random.randrange(10))
print(random.randrange(10, 20))
# Make one random number out of even numbers between 10 and 20
print(random.randrange(10, 20, 2))
# Random number is much used in sampling
for i in range(5):
print(random.randrange(10), end=' ')
# i can be removed because it's not used
# But it makes error
for in range(5):
print(random.randrange(10), end=' ')
# But since I still don't need i, I can make meaning of i weak
# "_" is called "placeholder"
for _ in range(5):
print(random.randrange(10), end=' ')
for _ in range(5):
# placeholder is variable or not? Just check it out
print(_)
# It turns out no error, so it's variable, you can use _ as variable
# But you don't need to use _ as variable
# _ is used not to use useless variable i
print(random.randrange(10), end=' ')
# When you do programming with random value,
# you can have cases when you don't want created random value to change
# To fix random value, you can use seed() which is much used
# But don't put seed() into inside of "for"
random.seed(1)
for _ in range(5):
print(random.randrange(10), end=' ')
print()
# Random number generating method
# This is used as global variable
next = 1
def rand():
# If you want to use global variable inside of method, you use global keyword
# Even if this syntax doesn't make error but this syntax must not be used
global next
# Following way to generate random value is called pseudo(fake) random number
# Following code generates different random values
next = next * 1103515245 + 12345
return int((next//65536) % 32768)
# Quiz
# Make method which can find the largest number out of 10 random numbers
# which are all smaller than 100
def maxNumber():
# Since I should find the largest number,
# I should create variable space to hold found number
# with initializing by 0
m = 0
# Since quize specified 10 numbers, we can loop 10 times
for _ in range(10):
# I generate 100 random numbers
n = random.randrange(100)
print(n, end=' ')
# And I compare generated random number to m
if m < n:
m = n
return m
# I refactor this method to make it general
def maxNumber():
m = -random.randrange(100)
print(m, end=' ')
for _ in range(10-1):
n = -random.randrange(100)
print(n, end=' ')
if m < n:
m = n
return m
print(maxNumber())
print('-'*50)
s1, s2 = sumOfOddEven()
print(s1, s2)
sum = sumOfOddEven()
print(sum)
]]>