Develop Reference

A better way to use , replace() in python

I built a pretty basic program ,,, that will take input in English ,, and encrypt it using random alphabets of different languages ;; And also decrypt it :-
def encrypt_decrypt():
inut = input("Text to convert ::-- ")
# feel free to replace the symbols ,, with ur own carecters or numbers or something
# u can also add numbers , and other carecters for encryption or decryption
decideing_variable = input("U wanna encrypt or decrypt ?? ,, write EN or DE ::- ")
if decideing_variable == "EN":
deep = inut.replace("a", "ᛟ").replace("b", "ᛃ").replace("c", "Ῡ").replace("d", "ϰ").replace("e", "Г").replace("f", "ξ").replace("g", "ᾫ").replace("h", "ῆ").replace("i", "₪").replace("j", "א").replace("k", "ⴽ").replace("l", "ⵞ").replace("m", "ⵥ").replace("n", "ঙ").replace("o", "Œ").replace("p", "უ").replace("q", "ক").replace("r", "ჶ").replace("s", "Ø").replace("t", "ю").replace("u", "ʧ").replace("v", "ʢ").replace("w", "ұ").replace("x", "Џ").replace("y", "န").replace("z", "໒")
print(f"\n{deep}\n")
elif decideing_variable == "DE":
un_deep = inut.replace("ᛟ", "a").replace("ᛃ", "b").replace("Ῡ", "c").replace("ϰ", "d").replace("Г", "e").replace("ξ","f").replace("ᾫ", "g").replace("ῆ", "h").replace("₪", "i").replace("א", "j").replace("ⴽ", "k").replace("ⵞ", "l").replace("ⵥ", "m").replace("ঙ", "n").replace("Œ", "o").replace("უ", "p").replace("ক", "q").replace("ჶ", "r").replace("Ø", "s").replace("ю", "t").replace("ʧ", "u").replace("ʢ", "v").replace("ұ", "w").replace("Џ", "x").replace("န", "y").replace("໒", "z")
print(f"\n{un_deep}\n")
encrypt_decrypt()
while writing this I didn't know any better way then chaining .replace() function ,,,
But I have a feeling , that this isn't the proper way to do it ,,
The code works fine .
But ,, does any one know a better way of doing this ?

It looks like you are doing a character by character replacement. The function you are looking for is string.maketrans. You can give strings of equal length to convert each character to the desired character. Here is a working example online:
# first string
firstString = "abc"
secondString = "def"
string = "abc"
print(string.maketrans(firstString, secondString))
# example dictionary
firstString = "abc"
secondString = "defghi"
string = "abc"
print(string.maketrans(firstString, secondString))
You can also look at the official documentation for further details.

You can make a dictionary for corresponding words and use this,
text = "ababdba"
translation = {'a':'ᛟ', 'b':'ᛃ', 'c':'Ῡ','d': 'ϰ','e': 'Г','f': 'ξ','g': 'ᾫ','h':'ῆ','i': '₪','j': 'א','k': 'ⴽ','l': 'ⵞ','m' :'ⵥ','n': 'ঙ','o': 'Œ','p': 'უ','q': 'ক','r': 'ჶ','s': 'Ø','t': 'ю','u': 'ʧ', 'v':'ʢ','w': 'ұ','x': 'Џ','y': 'န','z': '໒'}
def translate(text,translation):
result = []
for char in text:
result.append( translation[char] )
return "".join(result)
print(translate(text,translation))
result is
ᛟᛃᛟᛃϰᛃᛟ
This might help you.

str.translate() and str.maketrans() are built to do all of the replacements in one go.
e.g.
>>> encrypt_table = str.maketrans("abc", "ᛟᛃῩ")
>>> "an abacus".translate(encrypt_table)
'ᛟn ᛟᛃᛟῩus'
NB. not string.maketrans() which is how it used to be in Python 2, and is now outdated; Python 3 turned that into two systems, str.maketrans() for text and bytes.maketrans() for bytes. see How come string.maketrans does not work in Python 3.1?

Using regular expressions in python to extract location mentions in a sentence

I am writing a code using python to extract the name of a road,street, highway, for example a sentence like "There is an accident along Uhuru Highway", I want my code to be able to extract the name of the highway mentioned, I have written the code below.
sentence="there is an accident along uhuru highway"
listw=[word for word in sentence.lower().split()]
for i in range(len(listw)):
if listw[i] == "highway":
print listw[i-1] + " "+ listw[i]
I can achieve this but my code is not optimized, i am thinking of using regular expressions, any help please

'uhuru highway' can be found as follows
import re
m = re.search(r'\S+ highway', sentence) # non-white-space followed by ' highway'
print(m.group())
# 'uhuru highway'

If the location you want to extract will always have highway after it, you can use:
>>> sentence = "there is an accident along uhuru highway"
>>> a = re.search(r'.* ([\w\s\d\-\_]+) highway', sentence)
>>> print(a.group(1))
>>> uhuru

You can do the following without using regexes:
sentence.split("highway")[0].strip().split(' ')[-1]
First split according to "highway". You'll get:
['there is an accident along uhuru', '']
And now you can easily extract the last word from the first part.

String formatting in Python -textwrapper

I have a list of People=[Tom,Mike,Carol] and I want to print it in the the below format.
People Tom
Mike
Carol
Basically its the Title (People) some fixed tabs and then a list of the name in new line ( it sorta looks like a table). I want to achieve this using textwrap in Python but if there is any other possibility, I am open to that as well.
dedented_text = textwrap.dedent(' This is a test sentecne to see how well the textwrap works and hence using it here to test it').strip()
for width in [ 20 ]:
h='{0: <4}'.format('f')
k='{0: >4}'.format(textwrap.fill(dedented_text, width=20))
print h+k
Output:
f This is a test
sentecne to see how
well the textwrap
works and hence
using it here to
test it
Above i added my code for printing the Category and a sentence. But i'm not able to achieve what I want

Just print the first line separately then print the others in a loop:
print 'People ' + people[0]
for i in range(1, len(people)):
print ' ' * 7 + people[i]

Retrieving characters from a string using google app

I have written a small python program inside my google app. I am using it for extracting out specific characters out of a string like this
"+CMGL: 14,"REC READ","+918000459019",,"11/11/04,18:27:53+22"
C
"
I am using split function for it but it's not splitting the string.Any clues why?
it's giving me something this kind of [u'+CMGL: 14,"REC READ","+918000459019",,"11/11/04,18:27:53+22"\n C '] result.
def prog (self,strgs):
self.response.out.write(strgs)
temp1= strgs
self.response.out.write(temp1)
message_split=temp1.split('\n')
#self.response.out.write(message_split)
temp=message_split
self.response.out.write(temp)
message_split_second=strgs.split(',')
m_list=message_split[1:]
self.response.out.write(message_split_second)
collect_strings=''
for j in m_list:
collect_strings=collect_strings+j
message_txt=collect_strings
message_date=message_split_second[0]
message_date=message_date.replace('"',"")
dates=message_date
message_time=message_split_second[0]
message_time=message_time.split('/n')
message_time=message_time[0]
message_time=message_time.replace('"',"")
temp=message_time.split('+')
message_time=temp[0]
times=message_time
cell_number=message_split_second[0]
cell_number=cell_number.replace('"',"")
cellnum=cell_number
return message_txt,dates,times,cellnum

The splits in the first part of your function ought to work. Here's an experiment I just did in Python 2.6:
>>> s = '+CMGL: 14,"REC READ","+918000459019",,"11/11/04,18:27:53+22"\n C '
>>> s.split('\n')
['+CMGL: 14,"REC READ","+918000459019",,"11/11/04,18:27:53+22"', ' C ']
>>> s.split(',')
['+CMGL: 14', '"REC READ"', '"+918000459019"', '', '"11/11/04', '18:27:53+22"\n C ']
If your self.response.out.write calls aren't doing the same thing, try reducing the function to the very shortest thing that displays the odd behaviour. And check that you know exactly what's being passed in as the strgs argument.
I can't see much wrong with the rest, except that at one point you try to split on /n when you probably meant to use \n.

Python parsing

I'm trying to parse the title tag in an RSS 2.0 feed into three different variables for each entry in that feed. Using ElementTree I've already parsed the RSS so that I can print each title [minus the trailing )] with the code below:
feed = getfeed("http://www.tourfilter.com/dallas/rss/by_concert_date")
for item in feed:
print repr(item.title[0:-1])
I include that because, as you can see, the item.title is a repr() data type, which I don't know much about.
A particular repr(item.title[0:-1]) printed in the interactive window looks like this:
'randy travis (Billy Bobs 3/21'
'Michael Schenker Group (House of Blues Dallas 3/26'
The user selects a band and I hope to, after parsing each item.title into 3 variables (one each for band, venue, and date... or possibly an array or I don't know...) select only those related to the band selected. Then they are sent to Google for geocoding, but that's another story.
I've seen some examples of regex and I'm reading about them, but it seems very complicated. Is it? I thought maybe someone here would have some insight as to exactly how to do this in an intelligent way. Should I use the re module? Does it matter that the output is currently is repr()s? Is there a better way? I was thinking I'd use a loop like (and this is my pseudoPython, just kind of notes I'm writing):
list = bandRaw,venue,date,latLong
for item in feed:
parse item.title for bandRaw, venue, date
if bandRaw == str(band)
send venue name + ", Dallas, TX" to google for geocoding
return lat,long
list = list + return character + bandRaw + "," + venue + "," + date + "," + lat + "," + long
else
In the end, I need to have the chosen entries in a .csv (comma-delimited) file looking like this:
band,venue,date,lat,long
randy travis,Billy Bobs,3/21,1234.5678,1234.5678
Michael Schenker Group,House of Blues Dallas,3/26,4321.8765,4321.8765
I hope this isn't too much to ask. I'll be looking into it on my own, just thought I should post here to make sure it got answered.
So, the question is, how do I best parse each repr(item.title[0:-1]) in the feed into the 3 separate values that I can then concatenate into a .csv file?

Don't let regex scare you off... it's well worth learning.
Given the examples above, you might try putting the trailing parenthesis back in, and then using this pattern:
import re
pat = re.compile('([\w\s]+)\(([\w\s]+)(\d+/\d+)\)')
info = pat.match(s)
print info.groups()
('Michael Schenker Group ', 'House of Blues Dallas ', '3/26')
To get at each group individual, just call them on the info object:
print info.group(1) # or info.groups()[0]
print '"%s","%s","%s"' % (info.group(1), info.group(2), info.group(3))
"Michael Schenker Group","House of Blues Dallas","3/26"
The hard thing about regex in this case is making sure you know all the known possible characters in the title. If there are non-alpha chars in the 'Michael Schenker Group' part, you'll have to adjust the regex for that part to allow them.
The pattern above breaks down as follows, which is parsed left to right:
([\w\s]+) : Match any word or space characters (the plus symbol indicates that there should be one or more such characters). The parentheses mean that the match will be captured as a group. This is the "Michael Schenker Group " part. If there can be numbers and dashes here, you'll want to modify the pieces between the square brackets, which are the possible characters for the set.
\( : A literal parenthesis. The backslash escapes the parenthesis, since otherwise it counts as a regex command. This is the "(" part of the string.
([\w\s]+) : Same as the one above, but this time matches the "House of Blues Dallas " part. In parentheses so they will be captured as the second group.
(\d+/\d+) : Matches the digits 3 and 26 with a slash in the middle. In parentheses so they will be captured as the third group.
\) : Closing parenthesis for the above.
The python intro to regex is quite good, and you might want to spend an evening going over it http://docs.python.org/library/re.html#module-re. Also, check Dive Into Python, which has a friendly introduction: http://diveintopython3.ep.io/regular-expressions.html.
EDIT: See zacherates below, who has some nice edits. Two heads are better than one!

Regular expressions are a great solution to this problem:
>>> import re
>>> s = 'Michael Schenker Group (House of Blues Dallas 3/26'
>>> re.match(r'(.*) \((.*) (\d+/\d+)', s).groups()
('Michael Schenker Group', 'House of Blues Dallas', '3/26')
As a side note, you might want to look at the Universal Feed Parser for handling the RSS parsing as feeds have a bad habit of being malformed.
Edit
In regards to your comment... The strings occasionally being wrapped in "s rather than 's has to do with the fact that you're using repr. The repr of a string is usually delimited with 's, unless that string contains one or more 's, where instead it uses "s so that the 's don't have to be escaped:
>>> "Hello there"
'Hello there'
>>> "it's not its"
"it's not its"
Notice the different quote styles.

Regarding the repr(item.title[0:-1]) part, not sure where you got that from but I'm pretty sure you can simply use item.title. All you're doing is removing the last char from the string and then calling repr() on it, which does nothing.
Your code should look something like this:
import geocoders # from GeoPy
us = geocoders.GeocoderDotUS()
import feedparser # from www.feedparser.org
feedurl = "http://www.tourfilter.com/dallas/rss/by_concert_date"
feed = feedparser.parse(feedurl)
lines = []
for entry in feed.entries:
m = re.search(r'(.*) \((.*) (\d+/\d+)\)', entry.title)
if m:
bandRaw, venue, date = m.groups()
if band == bandRaw:
place, (lat, lng) = us.geocode(venue + ", Dallas, TX")
lines.append(",".join([band, venue, date, lat, lng]))
result = "\n".join(lines)
EDIT: replaced list with lines as the var name. list is a builtin and should not be used as a variable name. Sorry.