我需要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? 我需要将其结合到一个for
循环中。
我需要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? 我需要将其结合到一个for
循环中。
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)
这将返回一个包含数字的字符串列表。如果您实际上需要整数,可以使用 int
:
[int(x) for x in regex.findall(filename)]
如果每个文件名中只有一个数字,您可以使用regex.search(filename).group(0)
(如果您确定它会产生匹配)。 如果没有找到匹配项,上述行将生成一个AttributeError,指出NoneType
没有属性group
。os
模块获取文件名。re
的正则表达式,类似于这样:import re
def get_numbers_from_filename(filename):
return re.search(r'\d+', filename).group(0)
for filename in os.listdir(myfiledirectory):
print get_numbers_from_filename(filename)
如果只有一个数字:
filter(lambda x: x.isdigit(), filename)
# 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')