如何使用参数Python执行文件？

Question

I tried to to that like:

execfile('c:/xampp/mysql/bin/mysqldump -h localhost -u ' + username + ' -p' + password + ' ' + database + ' > ' + projectname + '.sql');

Then I see an error:

IOError: [Errno 2] No such file or directory: 'c:/xampp/mysql/bin/mysqldump -h localhost -u root -p pr > pr.sql'

What I do wrong?

I trie to write output to file like:

output = subprocess.check_output([r'c:\xampp\mysql\bin\mysqldump', '-h', 'localhost', '-u', username, '--password=', database], stdout=open(projectname + '.sql','w'))

It does not work

Answer 1

execfile doesn't take a whole command, but the name of the file to execute as the first argument. Moreover it's a way of calling other Python program, not a generic program - like mysqldump .

I suggest you use subprocess.call instead , eg

subprocess.call(['c:/xampp/mysql/bin/mysqldump', '-h', 'localhost', '-u', username, '-p' + password, database])

And then you need to take care of the redirection (typically done by your shell if you run it manually), so the full solution would be:

f = open(projectname+".sql", "w")
subprocess.call(['c:/xampp/mysql/bin/mysqldump', '-h', 'localhost', '-u', username, '-p' + password, database], stdout=f)

Answer 2

execfile is designed to run python files only (the name is misleading).

Plus it has been removed from Python 3...

For your issue, just use subprocess.check_output , splitting the arguments properly so quoting is handled automatically (never compose your command line by yourself). Here the -p option must have the password without spaces (that's a command specificity), or use --password which is clearer

output = subprocess.check_output([r'c:\xampp\mysql\bin\mysqldump', '-h', 'localhost', '-u', username, '--password', password, database])

Note: it seems that your password is blank (empty string), in that case, just use --password= like explained here

output = subprocess.check_output([r'c:\xampp\mysql\bin\mysqldump', '-h', 'localhost', '-u', username, '--password=', database])

now the output of your command is in output (if the command succeeds), you can write it into a file (well, in your case, it's true that you'be be better off with check_call and stdout=file_handle because you seem to need the .sql file, not only the buffer) anyway:

with open("file.sql","w") as f:
   f.write(output)