First Python 3 ~ The beginning of repetition ~

Introduction

Please refer to here for notes.

Iterative processing

History repeats itself.
Let's repeat a simple program.

Loop processing by for in

Simple iterative process.

for counter variable in repeat range:
Iterative processing

• Be careful not to forget the colon

Example

for i in range(3):
    print("hello world") 

============ ※ Execution result

hello world hello world hello world

============

Range function to repeat

The range function creates a range type object that has consecutive numerical values from the start number to the end number specified in the argument as elements.

• Range (a, b, x): Creates an object that has consecutive numerical values as elements up to the range that does not exceed the numerical value specified in x by adding the numerical values specified in b in order from the numerical value specified in a.
  -A and x can be omitted. In that case, a = 0 and x = 1.

range(5)
# 0 1 2 3 4

range(0, 5)
# 0 1 2 3 4

range(4,7)
# 4 5 6

range(0, 5, 1)
# 0 1 2 3 4

range(0, 10, 2)
# 0 2 4 6 8

range(10, 0, -1)
# 10 9 8 7 6 5 4 3 2 1

range(0, -8, -2)
# 0 -2 -4 -6

Try to specify with the range function

for i in range(6,11): # 6, 7, 8 ... 11
    print("Hello World:" + str(i)) #Display a numerical value behind
print("last " + str(i)) #For confirmation

============ ※ Execution result

Hello World:6 Hello World:7 Hello World:8 Hello World:9 Hello World:10 last 10

============

Repeat the numbers

Numerical values can also be repeated.

for i in range(10):
    print(i)

============ ※ Execution result

1
2
3
4
5
6
7
8
9

============

(Example) Display from January to December

for i in range(1,13):
    print(str(i) + "Month")

============ ※ Execution result

January
February
March
April
May
June
July
August
September
October
November
December

============

Iterative processing by while

A process that is repeated many times while the conditional expression is satisfied. You need to prepare the counter variables and conditional expressions yourself.

#while conditional expression:
    #Iterative processing
    #Update counter variable
    

• Be careful not to forget the colon

Example

Add the numbers and repeat until the number is less than or equal to the specified number or more than the specified number.

i = 1   #Initialization of counter variables
while i <= 10: #Execute if i is 10 or less(1,2,3,4...10)
    print(i)   #Iterative processing
    i = i + 1  #Updated counter variables. i= i +Repeat from 1 to 10
    print("Next:" + str(i)) # Next: 11
print("Last:" + str(i))

• If there is no update statement for the counter variable, it becomes a infinite loop </ b> (statement of "i = i + 1").

i = 5
while i <= 10:
    print(i)
    i += 1

i = 5
while i >= 1:
    print(i)
    i -= 1

import random
hp = 30
while hp > 0:
    hit = random.randint(1,10)
    print("To slime" + str(hit) + "Damaged!")
    hp -= hit
print("Defeated slime")

import random
hp = 1
while hp <= 150:
    kusa = random.randint(10,30)
    print("Use herbs to increase HP" + str(kusa) + "I recovered." + "Current HP:" + str(hp))
    hp += kusa
print("Full recovery of physical strength")