为什么我得到“FileNotFoundError：[Errno 2]没有这样的文件或目录：第20行的'无'”

Question

这是我的代码：

def translate():
    '''
    Prompts user to enter dictionary files and input and output files
    Changes words in input file according to the dictionary file
    Write translation in output file'''
    dictFileName = input('Enter name of dictionary: ')
    textFileName = input('Enter name of text file to translate: ')
    outputFileName = input('Enter name of output file: ' )
    f = open(dictFileName, 'r')
    xf = f.readlines()   # reads the whole file at once into a list
    j = open(textFileName,'r')
    xj = j.readlines()
    processedDictFileLines = [] # create empty list
    for line in dictFileLines: # begin for loop through lines in dictFileLines
        words = line.strip().split('|') # strip off the newline character and split the string into its constituent substrings separated by the '|' character
        processedDictFileLines.append(words[0] + ' ' + words[1])
    k=0
    while k<len(xj) :
        if xs[k] in processedDictFile:
            m=find(processedDictFile, xs[k])
            xs[k]=processedDictFile[m+1]
        k=k+1
    myfile = open(outputFileName, "w")
    myfile.write('xs')
    myfile.close()
    return myfile
translate()

但是如果我已经输入文件，为什么我会得到FileNotFoundError？