%%file argparse_tst.py
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#"""
#Created on July 19, 2014
#@author: bercherj
#"""

import argparse
import sys

whatitdoes="This program returns some interesting calculations."
myself="(c) JFB"
parser = argparse.ArgumentParser(description=whatitdoes, epilog=myself)

parser.add_argument(
# no option eg  '-o' '--output' --> positional argument
help = 'A number',
dest = 'num1',
default = 3,
type = int,
nargs = 1 # if '*' any number of arguments
)

parser.add_argument(
# no option eg  '-o' '--output' --> positional argument
help = 'A number',
dest = 'num2',
default = 3,
type = int,
nargs = 1 # if '*' any number of arguments
)

parser.add_argument('-o', dest='out', default=sys.stdout, 
                    help="optional output file", metavar='out-file', 
                    type=str)
# default=sys.stdout

parser.add_argument(
# no option eg  '-o' '--output' --> positional argument (no flag)
# but with a default value
help = 'A string',
dest = 'strarg',
default = 'Test',
type = str,
nargs = '?' # 0 or 1
)


parser.add_argument(
'-op',
'--operation',
help = 'An operation to apply to the two numbers',
dest = 'op',
default = 'add',
choices=('add','sub','mul','div','pow'),
action='store'
)

parser.add_argument(
'-f',
'--flag',
help = 'A flag',
dest = 'flag',
default = False,
action='store_true'
)

parser.add_argument(
'-v',
'--verbose',
help = 'Prints information',
dest = 'verbose',
default = False,
action='count'
)

def add(a,b): return a+b
def sub(a,b): return a-b
def mul(a,b): return a*b
def div(a,b): return a/b
def pow(a,b): return a**b

args = parser.parse_args()
op={'add':add, 'sub':sub, 'mul':mul, 'div':div, 'pow':pow}
op_string={'add':'addition', 'sub':'subtraction', 'mul':'multiplication', 
           'div':'division', 'pow':'power'}

verbose=args.verbose
out=open(args.out,"wt")
num1 = args.num1[0]
num2 = args.num2[0]

print("List of arguments: ", args, file=out)

if args.flag: 
    print("Flag f is set",file=out) 
else: 
    print("Flag f is not set",file=out)

if verbose: print("Computing the {0} of {1:d} and {2:d}".format(op_string[args.op],num1,num2),
                  file=out)
print("Result: ", op[args.op](num1,num2),file=out)
out.close()

%run argparse_tst -hIPython NotebookTest_argparse Last Checkpoint: Aug 05 22:39 (autosaved)
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title:  Some tests of argparse and configparser modules
slug: Argparse-configparser tests
date: 2014-08-05 22:12
tags: misc
comments: true
 
Here are some notes on two modules of the standard library that can help to develop small scripts. The module argparse helps to parse the arguments to the script while the module configparser is useful for reading a particular textfile configuration.
Argparse examples
The argparse module of the standard library is designed to ease the parsing of arguments to a script, either mandatory or optional. Besides, it offers a unix like help ans documentation of the script interface.The documentation is available in https://docs.python.org/dev/library/argparse.html, together with a howto. A tutorial is also available in Python Module of the Week.

%%file argparse_tst.py
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#"""
#Created on July 19, 2014
#@author: bercherj
#"""
 
import argparse
import sys
 
whatitdoes="This program returns some interesting calculations."
myself="(c) JFB"
parser = argparse.ArgumentParser(description=whatitdoes, epilog=myself)
 
parser.add_argument(
# no option eg  '-o' '--output' --> positional argument
help = 'A number',
dest = 'num1',
default = 3,
type = int,
nargs = 1 # if '*' any number of arguments
)
 
parser.add_argument(
# no option eg  '-o' '--output' --> positional argument
help = 'A number',
dest = 'num2',
default = 3,
type = int,
nargs = 1 # if '*' any number of arguments
)
 
parser.add_argument('-o', dest='out', default=sys.stdout, 
                    help="optional output file", metavar='out-file', 
                    type=str)
# default=sys.stdout
 
parser.add_argument(
# no option eg  '-o' '--output' --> positional argument (no flag)
# but with a default value
help = 'A string',
dest = 'strarg',
default = 'Test',
type = str,
nargs = '?' # 0 or 1
)
 
 
parser.add_argument(
'-op',
'--operation',
help = 'An operation to apply to the two numbers',
dest = 'op',
default = 'add',
choices=('add','sub','mul','div','pow'),
action='store'
)
 
parser.add_argument(
'-f',
'--flag',
help = 'A flag',
dest = 'flag',
default = False,
action='store_true'
)
 
parser.add_argument(
'-v',
'--verbose',
help = 'Prints information',
dest = 'verbose',
default = False,
action='count'
)
 
def add(a,b): return a+b
def sub(a,b): return a-b
def mul(a,b): return a*b
def div(a,b): return a/b
def pow(a,b): return a**b
 
args = parser.parse_args()
op={'add':add, 'sub':sub, 'mul':mul, 'div':div, 'pow':pow}
op_string={'add':'addition', 'sub':'subtraction', 'mul':'multiplication', 
           'div':'division', 'pow':'power'}
 
verbose=args.verbose
out=open(args.out,"wt")
num1 = args.num1[0]
num2 = args.num2[0]
 
print("List of arguments: ", args, file=out)
 
if args.flag: 
    print("Flag f is set",file=out) 
else: 
    print("Flag f is not set",file=out)
 
if verbose: print("Computing the {0} of {1:d} and {2:d}".format(op_string[args.op],num1,num2),
                  file=out)
print("Result: ", op[args.op](num1,num2),file=out)
out.close()
 
Overwriting argparse_tst.py

%run argparse_tst -h
usage: argparse_tst.py [-h] [-o out-file] [-op {add,sub,mul,div,pow}] [-f]
                       [-v]
                       num1 num2 [strarg]

%run argparse_tst 2 2 -op=add -vv -o=bibi.txt

cat bibi.txt

%%file proxies.cfg
[esiee]
http = http://cache.esiee.fr:3128/
https = http://cache.esiee.fr:3128/
[home]
http = http://proxy.domain.ext:3128/
https = http://proxy.domain.ext:3128/    

%%file configparser_tst.py

import argparse

whatitdoes="This program tests the config parser."
myself="(c) JFB"
parser = argparse.ArgumentParser(description=whatitdoes, epilog=myself)

parser.add_argument('-v','--verbose',help = 'Prints information',
dest = 'verbose',default = False,action='store_true')

parser.add_argument('-p','-proxy','--proxy',
    help = 'Takes proxy configuration from "proxies.cfg"',
dest = 'proxy',default = None,action='store')

args = parser.parse_args()
print(args)

proxies={}
if args.proxy: # if the proxy option has been specified in the arguments
    import configparser
    config = configparser.ConfigParser()
    s=config.read('proxies.cfg')
    if s: #if the cfg file exists
        try:
           proxies=dict(config[args.proxy])
        except KeyError: # the specified key does not correspond to a section in the cfg file
            print("'%s' is not a valid key for a proxy section" % args.proxy)
    else:
        print("The config file proxies.cfg does not exist in current directory")    

print('proxies= ',proxies)

%run configparser_tst.py -h

%run configparser_tst.py -p=zerg

%run configparser_tst.py -p=esiee

%%file translate_a_word.py
#author:jfb august 2014

import argparse
import urllib.parse
import urllib.request



### 1 ###  Script arguments and config ###################################
whatitdoes="This program translates a word from a language to another."
myself="(c) JFB"
parser = argparse.ArgumentParser(description=whatitdoes, epilog=myself)

parser.add_argument('-v','--verbose', help = 'Prints information',
dest = 'verbose',default = False, action='store_true')


parser.add_argument('-f','--from',help = 'translate from',dest = 'fro',
default = 'fr',choices=('en','de','fr','nl','es'),action='store')

parser.add_argument('-t','--to',help = 'translate to',dest = 'to',default = 'en',
choices=('en','de','fr','nl','es'),action='store')

parser.add_argument(help = 'word to translate',dest = 'word',default = 'hello',
nargs=1,action='store')

parser.add_argument('-p','-proxy','--proxy',
                    help = 'Takes proxy configuration from "proxies.cfg"',
dest = 'proxy',default = None,action='store')


args = parser.parse_args()

proxies={}
if args.proxy:
    import configparser
    config = configparser.ConfigParser()
    s=config.read('proxies.cfg')
    if s: #if the cfg file exists
        try:
           proxies=dict(config[args.proxy])
        except KeyError:
            print("'%s' is not a valid key for a proxy section" % args.proxy)
    else:
        print("The config file proxies.cfg does not exist in current directory")    

### 2 ### connects to the web service  ###################################
url = 'http://glosbe.com/gapi/translate'
values = {'from' : args.fro , 'dest' : args.to ,
              'format':'json' , 'phrase' : args.word[0] , 'pretty' : 'true', 'tm' : 'false'}
                       
proxy_handler = urllib.request.ProxyHandler(proxies)
opener = urllib.request.build_opener(proxy_handler)
response = opener.open(url+'/?'+urllib.parse.urlencode(values))
the_page = response.read().decode('latin1')
import json
page=json.loads(the_page)

### 3 ### Prints the translations  #########################################
# kind of result filtering
import html.parser
h = html.parser.HTMLParser()
for d in page['tuc']: 
    if 'phrase' in d.keys():
        if 'meanings' in d.keys(): 
            for k in range(len(d['meanings'])):
                 print(h.unescape(d['meanings'][k]['text']))
        print("-->",d['phrase']['text'])

page['tuc']

%run translate_a_word.py -h

%run translate_a_word.py -f=fr -t=es  bonjour

HTML(the_end(theNotebook))