Question

我只需从文件名中提取数字，例如：

GapPoints1.shp

GapPoints23.shp

GapPoints109.shp

如何使用Python从这些文件中提取数字？我需要将其合并到for循环中。

Answer 1

你可以使用正则表达式：

regex = re.compile(r'\d+')

然后获取匹配的字符串：

regex.findall(filename)

这将返回包含数字的字符串列表。如果您确实需要整数，可以使用int：

[int(x) for x in regex.findall(filename)]

如果每个文件名中只有1个数字，则可以使用regex.search(filename).group(0)（如果您确定它会产生匹配）。如果未找到匹配项，则上述行将生成一个AttributeError，指出NoneType没有属性group。

Answer 2

所以，你没有留下任何关于这些文件的位置以及如何获取这些文件的描述，但我假设您使用os模块获取文件名。

至于从名字中获取数字，你最好使用re的正则表达式，如下所示：

import re
def get_numbers_from_filename(filename):
    return re.search(r'\d+', filename).group(0)

然后，要在for循环中包含它，您将在每个文件名上运行该函数：

for filename in os.listdir(myfiledirectory):
   print get_numbers_from_filename(filename)

或类似的东西。

Answer 3

如果只有一个号码：

filter(lambda x: x.isdigit(), filename)

Answer 4

Hear是我的代码，在从Google Scholar下载文件后，我将论文的发表年份带到文件名的第一位。主要文件通常是这样构造的：Author + publishedYear.pdf因此，通过实现此代码，文件名将变为：PublishedYear + Author.pdf。

# Renaming Pdf according to number extraction
# You want to rename a pdf file, so the digits of document published year comes first.
# Use regular expersion
# As long as you implement this file, the other pattern will be accomplished to your filename.

# import libraries
import re
import os

# Change working directory to this folder
address = os.getcwd ()
os.chdir(address)

# defining a class with two function
class file_name:
    # Define a function to extract any digits
    def __init__ (self, filename):
        self.filename = filename

    # Because we have tow pattern, we must define tow function.
    # First function for pattern as : schrodinger1990.pdf
    def number_extrction_pattern_non_digits_first (filename):

        pattern = (r'(\D+)(\d+)(\.pdf)')
        digits_pattern_non_digits_first = re.search(pattern, filename, re.IGNORECASE).group (2) 
        non_digits_pattern_non_digits_first = re.search(pattern, filename, re.IGNORECASE).group (1)
        return digits_pattern_non_digits_first, non_digits_pattern_non_digits_first

    # Second function for pattern as : 1993schrodinger.pdf
    def number_extrction_pattern_digits_first (filename):

        pattern = (r'(\d+)(\D+)(\.pdf)')
        digits_pattern_digits_first = re.search(pattern, filename, re.IGNORECASE).group (1) 
        non_digits_pattern_digits_first = re.search(pattern, filename, re.IGNORECASE).group (2)

        return digits_pattern_digits_first, non_digits_pattern_digits_first



if __name__ == '__main__':

    # Define a pattern to check filename pattern
    pattern_check1 = (r'(\D+)(\d+)(\.pdf)')

    # Declare each file address.
    for filename in os.listdir(address):

        if filename.endswith('.pdf'):
            if re.search(pattern_check1, filename, re.IGNORECASE):

                digits = file_name.number_extrction_pattern_non_digits_first (filename)[0]
                non_digits = file_name.number_extrction_pattern_non_digits_first (filename)[1]
                os.rename(filename, digits + non_digits + '.pdf')

            # Else other pattern exists.    
            else :

                digits = file_name.number_extrction_pattern_digits_first (filename)[0]
                non_digits = file_name.number_extrction_pattern_digits_first (filename)[1]
                os.rename(filename, digits + non_digits + '.pdf')

如何从Python中提取文件名中的数字？

4 个答案: