python 기본 문법 문자열 자료형

# hello.py

print("Hello world")

## 주석
"""
hi test comment1
"""

'''
hi test comment2
'''
## print 
# string format - since python3
testString = 'I am {}'.format('Hwayoung')
print(testString)

print('Try python {} times'.format(3))

# f-string - since python3.6
country='Korea'
testfString = f'I am from {country}'
print(testfString)

## 자료형 숫자
# a의 b제곱
a=2
b=3
c=a**b
print(a**b)

# a 나누기 b의 몫
# print fstring format - since python3.6
print(f'a//b= {a//b}')

# a 나누기 b의 나머지
print(f'a%b= {a%b}')

## 자료형 문자열
print('I\'m 27')

# 문자열 곱하기
test = "hi"
print(test*3)

# 문자열 슬라이싱
a = "Life is too short, You need Python"
b = a[0:4] # 0<= a <3
print(b)

c =  a[19:]
print(c)

today = '20211215Rainy'
year = today[:4]
month = today[4:6]
day = today[6:8]
weather = today[8:]
print(f'{year} , {month} , {day} , {weather}')

# 문자열 변경
# Pithon -> Python 변경 방법
a = 'Pithon'
#a[1] = 'y' #error

b = a[:1]+'y'+a[2:] #right
print(b)

# 문자열 포매팅
a = 'I eat %d apples'% 3
print(a)

number =5
a = 'I eat %d apples %d bananas' %(number, 1)
print(a)

a = 'Error is %d%%' %92
print(a)

# 포맷 코드와 숫자 함께 사용하기
a = '%10sI\'m hwayoung' % 'hi'
print(a)

a = '%-10sI\'m hwayoung' % 'hi'
print(a)

# format 함수를 사용한 포매팅
a = 'I eat {0} apples {1} bananas'.format(3, 2)
print(a)

a = 'I eat {number1} apples {number2} bananas'.format(number1=4, number2=7)
print(a)

#dictionary
d = {'name':'Hwayoung', 'nationality':'Korea'}
a = f'My name is {d["name"]} from {d["nationality"]}'
print(a)

# 정렬
a = '{0:<10}'.format('hi') # left
print(a)

a = '{0:>10}'.format('hi') # right
print(a)

a = '{0:^10}'.format('hi') # center
print(a)


#문자열 삽입
a = ','.join('abcd')
print(a)

a = '\\'.join(['e','f','g','h'])
print(a)

# 왼쪽 공백 지우기 lstrip()
# rstrip()
# strip()