使用python re.match列出csv文件

Question

I have created a small code in python to list csv files in the current directory:

>>> for i in range(len(os.listdir())):
...     isMatch = re.search(r'\.csv$', os.listdir()[i])
...     if (isMatch):
...             print(os.listdir()[i])
...
HR_data.csv
HR_data2.csv
HR_data_WEKA.csv
WholesaleCustomersData.csv
>>>

Is there a more elegant and shorter way to do this, like using lambda expressions??? Thanks very much./

Answer 1

You don't need regex, and glob has overhead. Just use the inbuilt str.endswith function:

for filename in os.listdir():
    if filename.endswith('.csv'):
        print(filename)

Also, it is more efficient to iterate over the elements in a list directly than iterating over the indices and then referencing the list. Especially when you consider, you keep calling os.listdir() everytime you want to access the ith file, which is extremely wasteful.

---

Here's an elegant alternative with filter :

for csv_files in filter(lambda x: x.endswith('.csv'), os.listdir()):
    print(csv_files)

Works on both python2.x and 3.x.

Answer 2

from glob import glob

for f in glob('*.csv'):
    print(f)

Answer 3

Rather than using regex, you could try using Python's glob module:

import glob

files = glob.glob('*.csv')
for f in files:
    print(f)