1"""Collection of utilities for command-line interfaces and console scripts.""" 2import os 3import re 4 5 6numberAddedRE = re.compile(r"#\d+$") 7 8 9def makeOutputFileName(input, outputDir=None, extension=None, overWrite=False): 10 """Generates a suitable file name for writing output. 11 12 Often tools will want to take a file, do some kind of transformation to it, 13 and write it out again. This function determines an appropriate name for the 14 output file, through one or more of the following steps: 15 16 - changing the output directory 17 - replacing the file extension 18 - suffixing the filename with a number (``#1``, ``#2``, etc.) to avoid 19 overwriting an existing file. 20 21 Args: 22 input: Name of input file. 23 outputDir: Optionally, a new directory to write the file into. 24 extension: Optionally, a replacement for the current file extension. 25 overWrite: Overwriting an existing file is permitted if true; if false 26 and the proposed filename exists, a new name will be generated by 27 adding an appropriate number suffix. 28 29 Returns: 30 str: Suitable output filename 31 """ 32 dirName, fileName = os.path.split(input) 33 fileName, ext = os.path.splitext(fileName) 34 if outputDir: 35 dirName = outputDir 36 fileName = numberAddedRE.split(fileName)[0] 37 if extension is None: 38 extension = os.path.splitext(input)[1] 39 output = os.path.join(dirName, fileName + extension) 40 n = 1 41 if not overWrite: 42 while os.path.exists(output): 43 output = os.path.join( 44 dirName, fileName + "#" + repr(n) + extension) 45 n += 1 46 return output 47