尋找與取代
Python 中的正規表示法
Maria Eugenia Inzaugarat
Data scientist
尋找子字串
- 在目標字串中尋找指定子字串。
my_string = "Where's Waldo?"
my_string.find("Waldo")
8
my_string.find("Wenda")
-1
尋找子字串
- 在目標字串中尋找指定子字串。
my_string = "Where's Waldo?"
my_string.find("Waldo", 0, 6)
-1
index 函式
- 類似
.find()，在目標字串中尋找指定子字串。
my_string = "Where's Waldo?"
my_string.index("Waldo")
8
my_string.index("Wenda")
File "<stdin>", line 1, in <module>
ValueError: substring not found
index 函式
- 類似
.find()，在目標字串中尋找指定子字串。
my_string = "Where's Waldo?"
try:
my_string.index("Wenda")
except ValueError:
print("Not found")
"Not found"
計算出現次數
- 回傳指定子字串出現的次數。
my_string = "How many fruits do you have in your fruit basket?"
my_string.count("fruit")
2
my_string.count("fruit", 0, 16)
1
取代子字串
- 以新子字串取代原子字串的出現處。
my_string = "The red house is between the blue house and the old house"
print(my_string.replace("house", "car"))
The red car is between the blue car and the old car
print(my_string.replace("house", "car", 2))
The red car is between the blue car and the old house
