在if else语句中，else块在python中不起作用

Question

if (filenames.rfind(fileName) != -1):
    sftp.chmod(sftpPath + filenames, 0644)
    print (" Permission changed successfully ")
else:
    print (" No file available to process ")

In the above code if statement works but the else block doesnt work(its not printing if file is not available)

Answer 1

The syntax looks good, there is a probability that content of the variable 'filename' exists in some other string too other than the file you are testing. You may try to print the filename under if condition and try that out. You can also reduce your search scope by entering a beginning and end index, str.rfind(sub_str, beg=0 end=len(string)).