如何在Python中就地修改字符串?
不幸的是,您无法直接就地修改字符串,因为字符串是不可变的。只需从您想要从中收集的几个部分创建新字符串即可。不过,如果您仍需要能够修改就地 unicode 数据的对象,则应选择
- io.StringIO 对象
- 数组模块
让我们看看上面讨论的−
返回缓冲区的整个内容的字符串
示例
在这个示例中,我们将返回带有缓冲区的整个内容的字符串。我们有一个文本流 StringIO−
import io
myStr = "Hello, How are you?"
print("String = ",myStr)
# StringIO is a text stream using an in-memory text buffer
strIO = io.StringIO(myStr)
# The getvalue() returns a string containing the entire contents of the buffer
print(strIO.getvalue())
输出
String = Hello, How are you?
Hello, How are you?
现在,让我们更改流位置,写入新内容并显示
更改流位置并写入新字符串
示例
我们将看另一个示例,使用 seek() 方法更改流位置。使用 write() 方法在同一位置写入新字符串−
import io
myStr = "Hello, How are you?"
# StringIO is a text stream using an in-memory text buffer
strIO = io.StringIO(myStr)
# The getvalue() returns a string containing the entire contents of the buffer
print("String = ",strIO.getvalue())
# Change the stream position using seek()
strIO.seek(7)
# Write at the same position
strIO.write("How's life?")
# Returning the final string
print("Final String = ",strIO.getvalue())
输出
String = Hello, How are you?
Final String = Hello, How's life??
创建数组并将其转换为 Unicode 字符串
示例
在此示例中,使用数组() 创建数组,然后使用 tounicode() 方法将其转换为 Unicode 字符串−
import array
# Create a String
myStr = "Hello, How are you?"
# Array
arr = array.array('u',myStr)
print(arr)
# Modifying the array
arr[0] = 'm'
# Displaying the array
print(arr)
# convert an array to a unicode string using tounicode
print(arr.tounicode())
输出
array('u', 'Hello, How are you?')
array('u', 'mello, How are you?')
mello, How are you?