# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? ?通過單引號定義
? ? ?通過三個單引號定義
? ? ?通過三個雙引號定義
? ? '''

? ? a = 'this is string'
? ? b = '''this is string'''
? ? c = """this is string"""
? ? print(a, b, c)

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.capitalize() 將字符串首字母大寫
? ? '''
? ? a = 'i am xieruixiang'
? ? print(a.capitalize()) ?# I am xieruixiang

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.upper() 將字符串中所有字母大寫
? ? '''
? ? a = 'i am xieruixiang'
? ? print(a.upper()) ?# I AM XIERUIXIANG

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.lower(),string.casefold() 都能將字符串中所有字母小寫
? ? casefold是lower的加強版
? ? '''
? ? a = 'I AM XIERUIXIANG'
? ? print(a.lower()) ?# i am xieruixiang
? ? print(a.casefold()) ?# i am xieruixiang

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.swapcase() 能將字符串中的大寫變小寫，小寫變大寫。兩極反轉
? ? '''
? ? a = 'i AM xIErUIxIANG'
? ? print(a.swapcase()) ?# I am XieRuiXiang

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.zfill(width) 用0填充字符串到指定width長度，如果字符串長度大于等于width則不填充
? ? '''
? ? a = 'abcdef'
? ? print(a.zfill(6)) ?# abcdef
? ? print(a.zfill(10)) ?# 0000abcdef

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.count(item) 統計字符串中有幾個item
? ? '''
? ? a = 'abaacdef'
? ? print(a.count('a')) ?# 3
? ? print(a.count('aa')) ?# 1
? ? print(a.count('ha')) ?# 0

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.startswith(item) 判斷字符串是否以item開頭
? ? string.endswith(item) 判斷字符串是否以item結尾
? ? '''
? ? a = 'abaacdef'
? ? print(a.startswith('ab')) ?# True
? ? print(a.endswith('ef')) ?# False

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.find(item) 和 string.index(item) 都是查找item在字符串中第一次出現的位置
? ? string.find()找不到返回 -1
? ? string.index() 找不到返回錯誤
? ? 所以使用string.find() 更多
? ? '''
? ? a = 'abcedefg'
? ? print(a.find('c')) ?# 2
? ? print(a.index('c')) ?# 2
? ? print(a.find('ac')) ?# -1

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ?zstring.strip(char) 過濾字符。char為None則過濾等價空格的字符，否則過濾char字符，從左往右過濾一邊，從右往左再過濾一遍
? ? string.lstrip(char) 和strip() 相同，只不過該函數只從左往右過濾一遍
? ? string.rstrip(char) 和strip() 相同，只不過該函數只從右往左過濾一遍
? ? '''
? ? a = ' abcdefgh '
? ? b = ' ? ?abcdefgh ? ? '
? ? c = 'aabbaa'
? ? print(a.strip())
? ? print(b.strip())
? ? print(c.strip('a')) ?# bb
? ? print(c.lstrip('a')) ?# bbaa
? ? print(c.rstrip('a')) ?# aabb

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.replace(old,new,max) 將字符串中的old字符串替換成new字符串，替換max個，當max為None時替換全部
? ? '''
? ? a = 'abcdcdefg'
? ? print(a.replace('cd', 'ff')) ?# abffffefg
? ? print(a.replace('cd', 'ff', 1)) ?# abffcdefg
? ? print(a.replace('hh', 'ff')) ?# abcdcdefg

# coding:utf-8

if __name__ == '__main__':
? ? '''
? ? string.isspace() 判斷字符串是否僅僅由空格字符串構成
? ? string.istitle() 判斷所有單詞的首字母是否大寫
? ? string.isupper() 判斷所有英文字母是否大寫
? ? string.islower() 判斷所有英文字母是否小寫
? ? '''
? ? a = ' ? ? a ? ?'
? ? space = ' ? ? ? '
? ? title = 'I Love You'
? ? title2 = 'I Love you'
? ? upper = 'I LOVE YOU'
? ? upper2 = 'I LOVE You'
? ? lower = 'i love you'
? ? lower2 = 'I love you'
? ? print(space.isspace()) ?# True
? ? print(a.isspace()) ?# False
? ? print(title.istitle()) ?# True
? ? print(title2.istitle()) ?# False
? ? print(upper.isupper()) ?# True
? ? print(upper2.isupper()) ?# False
? ? print(lower.islower()) ?# True
? ? print(lower2.islower()) ?# False

# coding:utf-8

if __name__ == '__main__':

? ? a = 'abcdefg'?

print(a[::]) ?# abcdefg
? ? print(a[0:len(a):1]) ?# abcdefg

? ? print(a[::-1]) ?# gfedcba

? print(a[-2:-1:1]) ?# f