Question

我有很多输入文件，需要在其中替换少量字符串。首先，我使用正则表达式创建了一个使用键值对的字典。字典包含键（要替换的字符串）和值（替换）。

输入文件中的示例行：第一名学生的详细信息是FullName =“ABC XYZ KLM”FirstName =“ABC”ID =“123”

我的字典将是 - ＆gt;

student = {
    'ABC':'Student Firstname',
    'ABC XYZ KLM':'Student Fullname',
    '123':'Student ID'
    }

我正在使用字符串replace（）来替换，如下所示：

for line in inputfile1:
    for src, dst in student.items():
          line = line.replace(src,dst)

我的输出如下：第一个学生的详细信息是FullName =“学生名字XYZ KLM ”FirstName =“学生名字”ID =“学生ID”

我在寻找的是：第一个学生的详细信息是FullName =“学生姓名”FirstName =“学生姓名”ID =“学生ID”

你可以帮我解决这个问题吗？

Answer 1

这种情况正在发生，因为str.replace(..)首先替换ABC字符串。您需要确保首先替换最长的模式。为此，您可以按照以下选项之一进行操作：

选项1：

请使用OrderedDict字典，并在最短的字段之前输入要替换的最长字符串：

In [3]: from collections import OrderedDict

In [6]: student = OrderedDict([('ABC XYZ KLM', 'Student Fullname'),  ('ABC', 'Student Firstname'),('123', 'Student ID')])

In [7]: student.items()
Out[7]: 
[('ABC XYZ KLM', 'Student Fullname'),
 ('ABC', 'Student Firstname'),
 ('123', 'Student ID')]

In [8]: line = 'FullName ="ABC XYZ KLM" FirstName ="ABC" ID = "123"' 

In [9]: for src, dst in student.items():
   ...:        line = line.replace(src, dst)
In [10]: line 
Out[10]: 'FullName ="Student Fullname" FirstName ="Student Firstname" ID = "Student ID"'

整体代码如下所示：

from collections import OrderedDict
student = OrderedDict([('ABC XYZ KLM', 'Student Fullname'),
                       ('ABC', 'Student Firstname'),
                    ('123', 'Student ID')])
line = 'FullName ="ABC XYZ KLM" FirstName ="ABC" ID = "123"' 
for src, dst in student.items():
    line = line.replace(src, dst)

选项2：

同样正如@AlexHal在下面的评论中所建议的那样，您可以简单地使用元组列表并根据替换前的最长模式对其进行排序，代码将如下所示：

In [2]: student = [('ABC', 'Student Firstname'),('123', 'Student ID'), ('ABC XYZ KLM', 'Student Fullname')]

In [3]: sorted(student, key=lambda x: len(x[0]), reverse=True)
Out[3]: 
[('ABC XYZ KLM', 'Student Fullname'),
 ('ABC', 'Student Firstname'),
 ('123', 'Student ID')]

In [4]: sorted(student, key=lambda x: len(x[0]), reverse=True)
Out[4]: 
[('ABC XYZ KLM', 'Student Fullname'),
 ('ABC', 'Student Firstname'),
 ('123', 'Student ID')]

In [9]: line = ' "Details of first student are FirstName ="ABC" FullName ="ABC XYZ KLM" ID = "123"'

In [10]: for src, dst in sorted(student, key=lambda x: len(x[0]), reverse=True):
    ...:     line = line.replace(src, dst)
    ...:     

In [11]: line
Out[11]: ' "Details of first student are FirstName ="Student Firstname" FullName ="Student Fullname" ID = "Student ID"'

In [12]:

总代码：

student = [('ABC', 'Student Firstname'),
           ('123', 'Student ID'), 
           ('ABC XYZ KLM', 'Student Fullname')]

line = ' "Details of first student are FirstName ="ABC" FullName ="ABC XYZ KLM" ID = "123"'    
for src, dst in sorted(student, key=lambda x: len(x[0]), reverse=True):
    line = line.replace(src, dst)

如何在Python3中替换完整的字符串而不仅仅是子字符串

1 个答案:

选项1：

选项2：