I need to extract URLs from a column of DataFrame which was created using following values
creation_date,tweet_id,tweet_text
2020-06-06 03:01:37,1269102116364324865,#Webinar: Sign up for #SumoLogic's June 16 webinar to learn how to navigate your #Kubernetes environment and unders… https://stackoverflow.com/questions/42237666/extracting-information-from-pandas-dataframe
2020-06-06 01:29:38,1269078966985461767,"In this #webinar replay, #DisneyStreaming's #rothgar chats with #SumoLogic's #BenoitNewton about how #Kubernetes is… https://stackoverflow.com/questions/46928636/pandas-split-list-into-columns-with-regex
column name tweet_text contains URL. I am trying following code.
df["tweet_text"]=df["tweet_text"].astype(str)
pattern = r'https?:\/\/(www\.)?[-a-zA-Z0-9#:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()#:%_\+.~#?&//=]*)'
df['links'] = ''
df['links']= df["tweet_text"].str.extract(pattern, expand=True)
print(df)
I am using regex from answer of this question and it matches URL in both rows.
But I am getting NaN as values of new column df['links]'. I have also tried solution provided in first answer of this question, which was
df['links']= df["tweet_text"].str.extract(pattern, expand=False).str.strip()
But I am getting following error
AttributeError: 'DataFrame' object has no attribute 'str'
Lastly I created an empty column using df['links'] = '', because I was getting ValueError: Wrong number of items passed 2, placement implies 1 error. If that's relevant.
Can someone help me out here?
The main problem is that your URL pattern contains capturing groups where you need non-capturing ones. You need to replace all ( with (?: in the pattern.
However, it is not enough since str.extract requires a capturing group in the pattern so that it could return any value at all. Thus, you need to wrap the whole pattern with a capturing group.
You may use
pattern = r'(https?:\/\/(?:www\.)?[-a-zA-Z0-9#:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}[-a-zA-Z0-9()#:%_+.~#?&/=]*)'
Note the + is not necessary to escape inside a character class. Also, there is no need to use // inside a character class, one / is enough.
Related
I would like to create a variable to easily use the Adjusted Close price, which is simple for other single-worded attributes (like 'Close') but not that straightforward with Adjusted Close. How can I do the same thing I do here below with the column 'Close'?
end = dt.datetime.now()
start = end - dt.timedelta(weeks=104)
stocks_list = ['COST', 'NIO', 'AMD']
df = pdr.get_data_yahoo(stocks_list, start, end)
Close = df.Close
Close.head()
What you are referring to here is called Attribute Access in the documentation. Near the end of the section on Attribute access, there is the following warning:
You can use this access only if the index element is a valid Python
identifier, e.g. s.1 is not allowed. See here for an explanation of
valid identifiers.
From the linked documentation on what a valid identifier is:
Within the ASCII range (U+0001..U+007F), the valid characters for
identifiers are the same as in Python 2.x: the uppercase and lowercase
letters A through Z, the underscore _ and, except for the first
character, the digits 0 through 9.
Adjusted Close is not a valid python identifier (due to the space), so it will not be accessible as an attribute of your dataframe. There are also some other exceptions in the same warning that are worth reading about.
I would recommend an approach like BigBen suggests in the comments where you simply assign a local variable based on the column name as a string adjusted_close = df['Adjusted Close'].
If you are dead set on using Attribute access, you can mangle your column's name so it becomes a valid python identifier, and then you can use attribute access. From your example, this can be done with:
df.rename(columns = {"Adjusted Close" : "AdjustedClose"}, inplace = True)
Once you do this, you can access the Adjusted Close with df.AdjustedClose. I don't really recommend this approach, but it's possible.
I am using a regex function to return four OR 5 new fields: Store name, Details, Reason (optional), Pause time start, and Pause time end. Reason does not show up in every case like the other four fields. If it does show up, then it is between Store and Details within the text itself.
I am currently using this code to find the four required fields (which works):
parser = re.compile(r"your store, ([^,]+).*Details: ([^\n]*).*Created at: ([^\n]*).*Scheduled end time: ([^\n]*)", flags=re.DOTALL | re.MULTILINE)
df1['STORE']=''
df1['DETAILS']=''
df1['TIME_PAUSE_CREATED']=''
df1['TIME_PAUSE_END']=''
for index,i in enumerate(df1.DESCRIPTION):
txt = parser_reg.findall(i)
for field in txt:
df1['STORE'][index]=field[0]
df1['DETAILS'][index]=field[1]
df1['TIME_PAUSE_CREATED'][index]=field[2]
df1['TIME_PAUSE_END'][index]=field[3]
Is there a way to make an optional regex field and append that (else append 'Null') and continue scraping the other fields? I have tried using the following, but this only returns null values after store name:
parser = re.compile(r"your store, ([^,]+).*(Reason: ([^\n]*))?.*|Details: ([^\n]*).*)Created at: ([^\n]*).*Scheduled end time: ([^\n]*)", flags=re.DOTALL | re.MULTILINE)
Ideally I would be able to add the same respective column for 'Reason' like the other fields, but the regex expression still isn't working for me.
Thank you!
I take it from your example that Reason: is not always supplied? That's OK, just add it as an optional (one or zero occurrences) group. If it's not present, that capture group will be null. Between Store and Details add (?:Reason: (.*?))?. The final question mark says the whole Reason: section can occur zero or one times, making it optional. The whole regex (after a little extra cleanup) should read:
your store, ([^,]+).*?(?:Reason: (.*?))?\sDetails: (.*?)(?:\sDeactivation Time)?\sCreated at: (.*?[AP]M).*Scheduled end time: (.*?[AP]M)
Remember that Reason: will now be in field[1] and the other capture groups will be shifted down one.
I included this regex scanning your example string above from the Regex101 website.
Policy Id NPOH123414699 xyz OH 12605-12345 NASHVILLE TN 37101
Policy Id 9214234451
Policy Id AS12345FD ..... other info
I am trying to grab the number right after Id and only that and stop as soon as a space is encountered after the id. I don't know how to it.
my regex -->> "[P|p]olicy\s*[I|i]d\s*"
However it is capturing everything after Policy number and giving me this
NPOH123414699xyzOH1260512345NASHVILLETN37101
This is the regex without groups only full matches that u need to iterate (?<=Policy Id\s)\w+
here it is: https://regex101.com/r/8GEDs1/1
this simple pattern should be more than enough if you insist to use regex
a = re.findall(r"Id\s([0-9A-Z]+)", "Policy Id B1231232131 xysa da")[0]
You can:
(?<=\bPolicy Id\s)(\w+)
Reference:
https://regex101.com/r/LrzDX5/1
I am currently cleaning up a messy data sheet in which information is given in one excel cell where the different characteristics are not delimited (no comma, spaces are random).
Thus, my problem is to separate the different information without a delimitation I could use in my code (can't use a split command)
I assume that I need to include some characteristics of each part of information, such that the corresponding characteristic is recognized. However, I don't have a clue how to do that since I am quite new to Python and I only worked with R in the framework of regression models and other statistical analysis.
Short data example:
INPUT:
"WMIN CBOND12/05/2022 23554132121"
or
"WalMaInCBND 12/05/2022-23554132121"
or
"WalmartI CorpBond12/05/2022|23554132121"
EXPECTED OUTPUT:
"Walmart Inc.", "Corporate Bond", "12/05/2022", "23554132121"
So each of the "x" should be classified in a new column with the corresponding header (Company, Security, Maturity, Account Number)
As you can see the input varies randomly but I want to have the same output for each of the three inputs given above (I have over 200k data points with different companies, securities etc.)
First Problem is how to separate the information effectively without being able to use a systematic pattern.
Second Problem (lower priority) is how to identify the company without setting up a dictionary with 50 different inputs for 50k companies.
Thanks for your help!
I recommend to first introduce useful seperators where possible and construct a dictionary of replacements for processing with regular expressions.
import re
s = 'WMIN CBOND12/05/2022 23554132121'
# CAREFUL this not a real date regex, this should just
# illustrate the principle of regex
# see https://stackoverflow.com/a/15504877/5665958 for
# a good US date regex
date_re = re.compile('([0-9]{2}/[0-9]{2}/[0-9]{4})')
# prepend a whitespace before the date
# this is achieved by searching the date within the string
# and replacing it with itself with a prepended whitespace
# /1 means "insert the first capture group", which in our
# case is the date
s = re.sub(date_re, r' \1', s)
# split by one or more whitespaces and insert
# a seperator (';') to make working with the string
# easier
s = ';'.join(s.split())
# build a dictionary of replacements
replacements = {
'WMIN': 'Walmart Inc.',
'CBOND': 'Corporate Bond',
}
# for each replacement apply subsitution
# a better, but more replicated solution for
# this is given here:
# https://stackoverflow.com/a/15175239/5665958
for pattern, r in replacements.items():
s = re.sub(pattern, r, s)
# use our custom separator to split the parts
out = s.split(';')
print(out)
Using python and regular expressions:
import re
def make_filter(pattern):
pattern = re.compile(pattern)
def filter(s):
filtered = pattern.match(s)
return filtered.group(1), filtered.group(2), filtered.group(3), filtered.group(4)
return filter
filter = make_filter("^([a-zA-Z]+)\s([a-zA-Z]+)(\d+/\d+/\d+)\s(\d+)$")
filter("WMIN CBOND12/05/2022 23554132121")
The make_filter function is just an utility to allow you to modify the pattern. It returns a function that will filter the output according to that pattern. I use it with the "^([a-zA-Z]+)\s([a-zA-Z]+)(\d+/\d+/\d+)\s(\d+)$" pattern that considers some text, an space, some text, a date, an space, and a number. If you want to kodify this pattern provide more info about it. The output will be ("WMIN", "CBOND", "12/05/2022", "23554132121").
welcome! Yeah, we would definitely need to see more examples and regex seems to be the way to go... but since there seems to be no structure, I think it's better to think of this as seperate steps.
We KNOW there's a date which is (X)X/(X)X/XXXX (ie. one or two digit day, one or two digit month, four digit year, maybe with or without the slashes, right?) and after that there's numbers. So solve that part first, leaving only the first two categories. That's actually the easy part :) but don't lose heart!
if these two categories might not have ANY delimiter (for example WMINCBOND 12/05/202223554132121, or delimiters are not always delimiters for example IMAGINARY COMPANY X CBOND, then you're in deep trouble. :) BUT this is what we can do:
Gather a list of all the codes (hopefully you have that).
use str_detect() on each code and see if you can recognize the exact string in any of the dataset (if you do have the codes lemme know I'll write the code to do this part).
What's left after identifying the code will be the CBOND, whatever that is... so do that part last... what's left of the string will be that. Alternatively, you can use the same str_detect() if you have a list of whatever CBOND stuff is.
ONLY AFTER YOU'VE IDENTIFIED EVERYTHING, you can then replace the codes for what they stand for.
If you have the code-list let me know and I'll post the code.
edit
s = c("WMIN CBOND12/05/2022 23554132121",
"WalMaInCBND 12/05/2022-23554132121",
"WalmartI CorpBond12/05/2022|23554132121")
ID = gsub("([a-zA-Z]+).*","\\1",s)
ID2 = gsub(".* ([a-zA-Z]+).*","\\1",s)
date = gsub("[a-zA-Z ]+(\\d+\\/\\d+\\/\\d+).*","\\1",s)
num = gsub("^.*[^0-9](.*$)","\\1",s)
data.frame(ID=ID,ID2=ID2,date=date,num=num,stringsAsFactors=FALSE)
ID ID2 date num
1 WMIN CBOND 12/05/2022 23554132121
2 WalMaInCBND WalMaInCBND 12/05/2022-23554132121 12/05/2022 23554132121
3 WalmartI CorpBond 12/05/2022 23554132121
Works for cases 1 and 3 but I haven't figured out a logic for the second case, how can we know where to split the string containing the company and security if they are not separated?
So I am using a Magtek USB reader that will read card information,
As of right now I can swipe a card and I get a long string of information that goes into a Tkinter Entry textbox that looks like this
%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?
All of the data has been randomized, but that's the format
I've got a tkinter button (it gets the text from the entry box in the format I included above and runs this)
def printCD(self):
print(self.carddata.get())
self.card_data_get = self.carddata.get()
self.creditnumber =
self.card_data_get[self.card_data_get.find("B")+1:
self.card_data_get.find("^")]
print(self.creditnumber)
print(self.card_data_get.count("^"))
This outputs:
%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?
8954756016548963
This yields no issues, but if I wanted to get the next two variables firstname, and lastname
I would need to reuse self.variable.find("^") because in the format it's used before LAST and after INITIAL
So far when I've tried to do this it hasn't been able to reuse "^"
Any takers on how I can split that string of text up into individual variables:
Card Number
First Name
Last Name
Expiration Date
Regex will work for this. I didn't capture everything because you didn't detail what's what but here's an example of capturing the name:
import re
data = "%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?"
matches = re.search(r"\^(?P<name>.+)\^", data)
print(matches.group('name'))
# LAST/FIRST INITIAL
If you aren't familiar with regex, here's a way of testing pattern matching: https://regex101.com/r/lAARCP/1 and an intro tutorial: https://regexone.com/
But basically, I'm searching for (one or more of anything with .+ between two carrots, ^).
Actually, since you mentioned having first and last separate, you'd use this regex:
\^(?P<last>.+)/(?P<first>.+)\^
This question may also interest you regarding finding something twice: Finding multiple occurrences of a string within a string in Python
If you find regex difficult you can divide the problem into smaller pieces and attack one at a time:
data = '%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?'
pieces = data.split('^') # Divide in pieces, one of which contains name
for piece in pieces:
if '/' in piece:
last, the_rest = piece.split('/')
first, initial = the_rest.split()
print('Name:', first, initial, last)
elif piece.startswith('%B'):
print('Card no:', piece[2:])