Develop Reference

How to extract person name using regular expression?

I am new to Regular Expression and I have kind of a phone directory. I want to extract the names out of it. I wrote this (below), but it extracts lots of unwanted text rather than just names. Can you kindly tell me what am i doing wrong and how to correct it? Here is my code:
import re
directory = '''Mark Adamson
Home: 843-798-6698
(424) 345-7659
265-1864 ext. 4467
326-665-8657x2986
E-mail:madamson#sncn.net
Allison Andrews
Home: 612-321-0047
E-mail: AEA#anet.com
Cellular: 612-393-0029
Dustin Andrews'''
nameRegex = re.compile('''
(
[A-Za-z]{2,25}
\s
([A-Za-z]{2,25})+
)
''',re.VERBOSE)
print(nameRegex.findall(directory))
the output it gives is:
[('Mark Adamson', 'Adamson'), ('net\nAllison', 'Allison'), ('Andrews\nHome', 'Home'), ('com\nCellular', 'Cellular'), ('Dustin Andrews', 'Andrews')]
Would be really grateful for help!

Your problem is that \s will also match newlines. Instead of \s just add a space. That is
name_regex = re.compile('[A-Za-z]{2,25} [A-Za-z]{2,25}')
This works if the names have exactly two words. If the names have more than two words (middle names or hyphenated last names) then you may want to expand this to something like:
name_regex = re.compile(r"^([A-Za-z \-]{2,25})+$", re.MULTILINE)
This looks for one or more words and will stretch from the beginning to end of a line (e.g. will not just get 'John Paul' from 'John Paul Jones')

I can suggest to try the next regex, it works for me:
"([A-Z][a-z]+\s[A-Z][a-z]+)"

The following regex works as expected.
Related part of the code:
nameRegex = re.compile(r"^[a-zA-Z]+[',. -][a-zA-Z ]?[a-zA-Z]*$", re.MULTILINE)
print(nameRegex.findall(directory)
Output:
>>> python3 test.py
['Mark Adamson', 'Allison Andrews', 'Dustin Andrews']

Try:
nameRegex = re.compile('^((?:\w+\s*){2,})$', flags=re.MULTILINE)
This will only choose complete lines that are made up of two or more names composed of 'word' characters.

How to separate the prefix in words that are 'di'?

I want to separate some prefixes that are integrated into words after the word "di" is followed by letters.
sentence1 = "dipermudah diperlancar"
sentence2 = "di permudah di perlancar"
I expect the output like this:
output1 = "di permudah di perlancar"
output2 = "di permudah di perlancar"
Demo

This expression might work to some extent:
(di)(\S+)
if our data would just look like as simple as is in the question. Otherwise, we would be adding more boundaries to our expression.
Test
import re
regex = r"(di)(\S+)"
test_str = "dipermudah diperlancar"
subst = "\\1 \\2"
print(re.sub(regex, subst, test_str))
The expression is explained on the top right panel of regex101.com, if you wish to explore/simplify/modify it, and in this link, you can watch how it would match against some sample inputs, if you like.

Here is one way to do this using re.sub:
sentence1 = "adi dipermudah diperlancar"
output = re.sub(r'(?<=\bdi)(?=\w)', ' ', sentence1)
print(output)
Output:
adi di permudah di perlancar
The idea here is to insert a space whenever what immediately precedes is the prefix di, and what also follows is some other word character.

Using Regular expressions to match a portion of the string?(python)

What regular expression can i use to match genes(in bold) in the gene list string:
GENE_LIST: F59A7.7; T25D3.3; F13B12.4; cysl-1; cysl-2; cysl-3; cysl-4; F01D4.8
I tried : GENE_List:((( \w+).(\w+));)+* but it only captures the last gene

Given:
>>> s="GENE_LIST: F59A7.7; T25D3.3; F13B12.4; cysl-1; cysl-2; cysl-3; cysl-4; F01D4.8"
You can use Python string methods to do:
>>> s.split(': ')[1].split('; ')
['F59A7.7', 'T25D3.3', 'F13B12.4', 'cysl-1', 'cysl-2', 'cysl-3', 'cysl-4', 'F01D4.8']
For a regex:
(?<=[:;]\s)([^\s;]+)
Demo
Or, in Python:
>>> re.findall(r'(?<=[:;]\s)([^\s;]+)', s)
['F59A7.7', 'T25D3.3', 'F13B12.4', 'cysl-1', 'cysl-2', 'cysl-3', 'cysl-4', 'F01D4.8']

You can use the following:
\s([^;\s]+)
Demo
The captured group, ([^;\s]+), will contain the desired substrings followed by whitespace (\s)
>>> s = 'GENE_LIST: F59A7.7; T25D3.3; F13B12.4; cysl-1; cysl-2; cysl-3; cysl-4; F01D4.8'
>>> re.findall(r'\s([^;\s]+)', s)
['F59A7.7', 'T25D3.3', 'F13B12.4', 'cysl-1', 'cysl-2', 'cysl-3', 'cysl-4', 'F01D4.8']

UPDATE
It's in fact much simpler:
[^\s;]+
however, first use substring to take only the part you need (the genes, without GENELIST )
demo: regex demo

string = "GENE_LIST: F59A7.7; T25D3.3; F13B12.4; cysl-1; cysl-2; cysl-3; cysl-4; F01D4.8"
re.findall(r"([^;\s]+)(?:;|$)", string)
The output is:
['F59A7.7',
'T25D3.3',
'F13B12.4',
'cysl-1',
'cysl-2',
'cysl-3',
'cysl-4',
'F01D4.8']

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.

Python regex: Match ALL consecutive capitalized words

Short question:
I have a string:
title="Announcing Elasticsearch.js For Node.js And The Browser"
I want to find all pairs of words where each word is properly capitalized.
So, expected output should be:
['Announcing Elasticsearch.js', 'Elasticsearch.js For', 'For Node.js', 'Node.js And', 'And The', 'The Browser']
What I have right now is this:
'[A-Z][a-z]+[\s-][A-Z][a-z.]*'
This gives me the output:
['Announcing Elasticsearch.js', 'For Node.js', 'And The']
How can I change my regex to give desired output?

You can use this:
#!/usr/bin/python
import re
title="Announcing Elasticsearch.js For Node.js And The Browser TEst"
pattern = r'(?=((?<![A-Za-z.])[A-Z][a-z.]*[\s-][A-Z][a-z.]*))'
print re.findall(pattern, title)
A "normal" pattern can't match overlapping substrings, all characters are founded once for all. However, a lookahead (?=..) (i.e. "followed by") is only a check and match nothing. It can parse the string several times. Thus if you put a capturing group inside the lookahead, you can obtain overlapping substrings.

There's probably a more efficient way to do this, but you could use a regex like this:
(\b[A-Z][a-z.-]+\b)
Then iterate through the capture groups like so testing with this regex: (^[A-Z][a-z.-]+$) to ensure the matched group(current) matches the matched group(next).
Working example:
import re
title = "Announcing Elasticsearch.js For Node.js And The Browser"
matchlist = []
m = re.findall(r"(\b[A-Z][a-z.-]+\b)", title)
i = 1
if m:
for i in range(len(m)):
if re.match(r"(^[A-Z][a-z.-]+$)", m[i - 1]) and re.match(r"(^[A-Z][a-z.-]+$)", m[i]):
matchlist.append([m[i - 1], m[i]])
print matchlist
Output:
[
['Browser', 'Announcing'],
['Announcing', 'Elasticsearch.js'],
['Elasticsearch.js', 'For'],
['For', 'Node.js'],
['Node.js', 'And'],
['And', 'The'],
['The', 'Browser']
]

If your Python code at the moment is this
title="Announcing Elasticsearch.js For Node.js And The Browser"
results = re.findall("[A-Z][a-z]+[\s-][A-Z][a-z.]*", title)
then your program is skipping odd numbered pairs. An easy solution would be to research the pattern after skipping the first word like this:
m = re.match("[A-Z][a-z]+[\s-]", title)
title_without_first_word = title[m.end():]
results2 = re.findall("[A-Z][a-z]+[\s-][A-Z][a-z.]*", title_without_first_word)
Now just combine results and result2 together.