python學習筆記之基礎操作（二）字符串操作（2）

#二：替換操作
#replace():替換指定字符串
test = "123abcefsdfa"
print(test.replace("123","___"))

___abcefsdfa

#swapcase():轉換大小寫:
test = "asdfgVBNMK"
print(test.swapcase())

ASDFGvbnmk

#upper(),lower()
print(test.upper())
print(test.lower())

ASDFGVBNMK
asdfgvbnmk

#三，分割操作
#split():按照指定字符串分割字符，可以指定分割的數量
test = "123,456,789"
print(test.split(","))
print(test.split(",",1))

['123', '456', '789']
['123', '456,789']

#partition()按照指定字符串分割爲兩部分,包含分隔符
#rpartition()，右面第一個開始分割
print(test.partition(","))
print(test.rpartition(","))

('123', ',', '456,789')
('123,456', ',', '789')

#四：查找操作
#find():找不到返回-1
test = "12345672"
print(test.find("2"))
print(test.rfind("2"))
print(test.find("a"))

1
7
-1

#index同上，不過返回錯誤找不到的話
print(test.index("2"))
print(test.rindex("2"))
print(test.index("a"))

1
7



---------------------------------------------------------------------------

ValueError                                Traceback (most recent call last)

<ipython-input-17-af7b2106d969> in <module>()
      2 print(test.index("2"))
      3 print(test.rindex("2"))
----> 4 print(test.index("a"))


ValueError: substring not found