How to read the filenames from an input directory that starts with the prefixes in a list in python-CodePudding

I am using the current function to read file from a local directory when the filename starts with certain prefix. Now I have second use case where multiple prefixes are in a list like['prefix1', 'prefix2'] . How can I modify the code below for finding multiple filenames from the local directory where filename start with prefixes in the list? If I use the current function than it gives error as now the prefix is not string but list.

if dev:
    print('Reading files from dowloaded data')
    for filename in os.listdir('Data\Input_data'):
        if prefix in filename:
            print ('using downloaded file',filename)
            df_file = os.path.join ('Data\Input_data',filename)
            if df == None:
                df = df_file
            else:
                df.append(df_file)

CodePudding user response：

The issue is about this line:

if prefix in filename

The logic will be inversed like this:

if (some part of the filename) in prefix , where prefix is a list like['prefix1', 'prefix2',..]

You can solve this using startswith method and a tuple of the prefixes list.

For example:

prefix_list=['prefix1', 'prefix2','prefix3', 'prefix3']
filename="prefix30000"
print(filename.startswith(tuple(prefix_list)))
#True

Then you can modify your code like this:

if dev:
    print('Reading files from dowloaded data')
    for filename in os.listdir('Data\Input_data'):
        if filename.startswith(tuple(prefix)): # << Updated line
            print ('using downloaded file',filename)
            df_file = os.path.join ('Data\Input_data',filename)
            if df == None:
                df = df_file
            else:
                df.append(df_file)