I have requirement where I am reading a string from json file and assign values to it to make it as a configurable file name.
String I am reading from json:
data_file_format = "sourcesystem_batchid_extractname_loadtype" I have variable which holds the values in my code like
sourcesystem ="xyz" batchid = "101" extractname = "abc" loadtype = "Delta" so my data_file_format should yeild value like
data_file_format = "xyz_101_abc_Delta" There are multiple methods to do that.:
fstring
data_file_format = f'{sourcesystem}_{batchid}_{extractname}_{loadtype}' or using .format
data_file_format = '{}_{}_{}_{}'.format(sourcetype,batchid,extractname,loadtype) 
sourcesystem ="xyz" batchid = "101" extractname = "abc" loadtype = "Delta" data_file_format="_".join([sourcesystem,batchid,extractname,loadtype]) #or #data_file_format=sourcesystem+'_'+batchid +'_'+extractname+'_'+loadtype print(data_file_format) So, you need to dynamically generate a file name based on an input data_file_format. Can you store your data in a dict instead of separate variables?
data_file_format = "sourcesystem_batchid_extractname_loadtype" data = { "sourcesystem": "xyz", "batchid": "101", "extractname": "abc", "loadtype": "Delta" } filename = '_'.join([data[key] for key in data_file_format.split('_')]) print(filename) xyz_101_abc_Delta
.join would be the best answer in this scenario (the answer by bitto). But for the future some good methods are:
>>> a = 1 >>> b = 2 >>> c = "three" >>> "%d and %d then %s" % (a, b, c) 1 and 2 then three >>> "{} and {} then {}".format(a, b, c) 1 and 2 then three >>> f"{a} and {b} then {c}" 1 and 2 then three Or you can go basic and go ahead like,
data_file_format = datasourcesystem + "_" + batchid + "_" + extractname + "_" + loadtype The previous answer is not far off too. It just forgot the underscores
you can concat strings in python with +
data_file_format = sourcesystem + "_" + batchid + "_" + extractname + "_" + loadtype this should give you "xyz_101_abc_Delta"
