查找与替换
Python 中的正则表达式
Maria Eugenia Inzaugarat
Data scientist
查找子串
- 在目标字符串中查找指定子串。
my_string = "Where's Waldo?"
my_string.find("Waldo")
8
my_string.find("Wenda")
-1
查找子串
- 在目标字符串中查找指定子串。
my_string = "Where's Waldo?"
my_string.find("Waldo", 0, 6)
-1
index 函数
- 类似于
.find()，在目标字符串中查找指定子串。
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 函数
- 类似于
.find()，在目标字符串中查找指定子串。
my_string = "Where's Waldo?"
try:
my_string.index("Wenda")
except ValueError:
print("Not found")
"Not found"
统计出现次数
- 返回指定子串的出现次数。
my_string = "How many fruits do you have in your fruit basket?"
my_string.count("fruit")
2
my_string.count("fruit", 0, 16)
1
替换子串
- 用新子串替换目标子串的出现。
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
