[Python] Minutes of study meeting for beginners (7/15)

7/15 21: 00 ~ Held at ZOOM

agenda

――By the way, what is Bool type? --while statement --break statement --Chat

By the way, what is the Bool type?

Bool types have True and False.

Use the type method to check the type of the object you normally use.

Try: Let's reconfirm what type of object we usually use.

Answer example

Example

print(type(1)) 
# => <class 'int'>
print(type('hogehoge'))
# => <class 'str'>
print(type(False))
# => <class 'bool'>
print(type(Ture))
# => <class 'bool'>

A conditional expression of an if statement that is used casually. The contents are basically Bool type. In other words, when creating a condition, make sure that the formula is a Bool type.

python

hoge = True
if hoge:
    print('The contents of hoge is True')
else:
    print('The contents of hoge is False')
# =>The contents of hoge is True

By the way, operators such as ==, > and ʻor`, which are often used in conditional expressions, are also returned as Bool type.

python

a = 0
b = 1
print(a == b)
# => False
print(a < b)
# => True
print(a == b or a < b)
# => True

So far, the basics are basic, but just knowing that the conditional expression is a Bool type, it seems that the if statement that I have already studied and the while statement that I will study will be easier to understand, so I added it to the agenda.

As an application, since true and 1, false and 0 are equivalent

python

print(True == 1)
print(False == 0)

Both return True. Find out why this happens.

while statement

The while statement is the basic syntax used for iterative processing.

python

while conditional expression:
Iterative processing when the condition is True

For example, when "output 1 to 10"

python

i = 1  #It is called a loop variable. Prepare to count
while i <= 10:
    print(f'The numbers are{i}')
    i += 1  #I'm adding one by one. Without this, the condition would be True and an infinite loop.

Try: Let's output 2 to the 0th power to 2 to the 10th power. (Any number to the 0th power is 1)

Answer example

Example

i = 0
while i <=10:
    print(2 ** i)  #  **Find the multiplier with the operator
    i += 1

break statement

The break statement is used to get out of the iterative process.

python

i = 0
while 1:
    print(i)
    if i > 2:
        break
    i += 1
# => 0
# => 1
# => 2
# => 3

Try: Let's create a program that outputs "Please enter characters" until "exit" is entered. By the way, why does while 1: make an infinite loop? Let's go back to the Bool type story

Answer example

Example

while 1:
    str = input('Please enter the characters>> ')
    if str == 'exit':
        break

Chat