import os
os.getcwd()


os.listdir(os.curdir)


os.mkdir('junkdir')
'junkdir' in os.listdir(os.curdir)




fp = open('junk.txt', 'w')    # first create an empty file
fp.close()


fp = open('junk.txt', 'w')


import subprocess
subprocess.call('chmod +x rst2py.py', shell=True)


output = subprocess.check_output(['ls','-all','-h'])
print(output)


import urllib
url = urllib.FancyURLopener()
link = 'http://www.ster.kuleuven.be/~pieterd/some_program.f'
myfile,msg = url.retrieve(link, filename='some_program.f')
url.close()
output = subprocess.check_call('gfortran some_program.f',shell=True)
print(output) # output flag of zero means successful


p1 = subprocess.Popen('./a.out',stdout=subprocess.PIPE)
print(p1.stdout.readline())


import signal
p1.send_signal(signal.SIGSTOP) # temporarily halt the executing of a program
p1.send_signal(signal.SIGCONT) # continue the program
p1.send_signal(signal.SIGKILL) # kill the program


os.remove('a.out')


from glob import glob


sorted(glob('[hn]*.txt'))