I need a unique regex to replace a substring or add it if missing.
Example:
set beta=10
"alpha=25 beta=42 delta=43" need to become "alpha=25 beta=10 delta=43"
"alpha=25 delta=43" need to become "alpha=25 delta=43 beta=10"
This following code is functional only to replace existing value, but if the index to replace does not already exist it does not add anything.
dest = re.sub(r'(.*)(beta=\d+)( .*)',r'\1 beta=10 \3',source)
I can do that, but I need this result in one expression:
if re.search(r'beta=\d+',source):
dest = re.sub(r'(.*)(beta=\d+)( .*)',r'\1 beta=10 \3',source)
else:
dest = source + " beta=10"
So if beta=xx exist in a string and it doesn't match beta=yy then replace
So if beta=xx does not exist in a string then append beta=yy to string
Assuming that beta=10 is only present 0 or 1 times in the string, you could do it like this:
dest = re.sub("(beta=\d+|$)","beta=10",source+" ",1).strip()
The pattern considers the end of line to be an alternative match for beta=\d+ and, since we're only substituting the first occurrence, it will only apply when the line does not contain beta=\d+
Related
I have a long string that may contain multiple same sub-strings. I would like to extract certain sub-strings by using regex. Then, for each extracted sub-string, I want to append [i] and replace the original one.
By using Regex, I extracted ['df.Libor3m','df.Libor3m_lag1','df.Libor3m_lag1']. However, when I tried to add [i] to each item, the first 'df.Libor3m_lag1' in string is replaced twice.
function_text_MD='0.11*(np.maximum(df.Libor3m,0.9)-np.maximum(df.Libor3m_lag1,0.9))+0.7*np.maximum(df.Libor3m_lag1,0.9)'
read_var = re.findall(r"df.[\w+][^\W]+",function_text_MD)
for var_name in read_var:
function_text_MD.find(var_name)
new_var_name = var_name+'[i]'
function_text_MD=function_text_MD.replace(var_name,new_var_name,1)
So I got '0.11*(np.maximum(df.Libor3m[i],0.9)-np.maximum(df.Libor3m_lag1[i][i],0.9))+0.7*np.maximum(df.Libor3m_lag1,0.9)'.
df.Libor3m_lag1[i][i] was added [i] twice.
What I want to get:
'0.11*(np.maximum(df.Libor3m[i],0.9)-np.maximum(df.Libor3m_lag1[i],0.9))+0.7*np.maximum(df.Libor3m_lag1[i],0.9)'
Thanks in advance!
Here is the code.
import re
function_text_MD='0.11*(np.maximum(df.Libor3m,0.9)-np.maximum(df.Libor3m_lag1,0.9))+0.7*np.maximum(df.Libor3m_lag1,0.9)'
read_var = re.findall(r"df.[\w+][^\W]+",function_text_MD)
for var_name in read_var:
function_text_MD = function_text_MD.replace(var_name,var_name+'[i]')
print(function_text_MD)
t = "0.11*(np.maximum(df.Libor3m,0.9)-np.maximum(df.Libor3m_lag1,0.9))+0.7*np.maximum(df.Libor3m_lag1,0.9)"
p = re.split("(?<=df\.)[a-zA-Z_0-9]+", t)
s = re.findall("(?<=df\.)[a-zA-Z_0-9]+", t)
s = [x+"[i]" for x in s]
result = "".join([p[0],s[0],p[1],s[1],p[2],s[2]])
use the regular expression to split string first.
use the same regular expression to find the spliters
change the spliters to what you want
put the 2 list together and join.
A small issue I've encountered during coding.
I'm looking to print out the name of a .txt file.
For example, the file is named: verdata_florida.txt, or verdata_newyork.txt
How can I exclude .txt and verdata_, but keep the string between? It must work for any number of characters, but .txt and verdata_ must be excluded.
This is where I am so far, I've already defined filename to be input()
print("Average TAM at", str(filename[8:**????**]), "is higher than ")
3 ways of doing it:
using str.split twice:
>>> "verdata_florida.txt".split("_")[1].split(".")[0]
'florida'
using str.partition twice (you won't get an exception if the format doesn't match, and probably faster too):
>>> "verdata_florida.txt".partition("_")[2].partition(".")[0]
'florida'
using re, keeping only center part:
>>> import re
>>> re.sub(".*_(.*)\..*",r"\1","verdata_florida.txt")
'florida'
all those above must be tuned if _ and . appear multiple times (must we keep the longest or the shortest string)
EDIT: In your case, though, prefixes & suffixes seem fixed. In that case, just use str.replace twice:
>>> "verdata_florida.txt".replace("verdata_","").replace(".txt","")
'florida'
Assuming you want it to split on the first _ and the last . you can use slicing and the index and rindex functions to get this done. These functions will search for the first occurrence of the substring in the parenthesis and return the index number. If no substring is found, they will throw a ValueError. If the search is desired, but not the ValueError, you can also use find and rfind, which do the same thing but always return -1 if no match is found.
s = 'verdata_new_hampshire.txt'
s_trunc = s[s.index('_') + 1: s.rindex('.')] # or s[s.find('_') + 1: s.rfind('.')]
print(s_trunc) # new_hampshire
Of course, if you are always going to exclude verdata_ and .txt you could always hardcode the slice as well.
print(s[8:-4]) # new_hampshire
You can leverage str.split() on strings. For example:
s = 'verdata_newyork.txt'
s.split('verdata_')
# ['', 'florida.txt']
s.split('verdata_')[1]
# 'florida.txt'
s.split('verdata_')[1].split('.txt')
['florida', '']
s.split('verdata_')[1].split('.txt')[0]
# 'florida'
You can just split string by dot and underscore like this:
string filename = "verdata_prague.txt";
string name = filename.split("."); //verdata_prague
name = name[0].split("_")[1]; //prague
or by replace function:
string filename = "verdata_prague.txt";
string name = filename.replace(".txt",""); //verdata_prague
name = name[0].replace("verdata_","")[1]; //prague
In sikuli I've get a multiline string from clipboard like this...
Names = App.getClipboard();
So Name =
#corazona
#Pebleo00
#cofriasd
«paflio
and I have use this regex to delete the first character if it is not in x00-x7f hex range or is not a word, or is a digit
import re
Names = re.sub(r"(?m)^([^\x00-\x7F]+|\W|\d)", "", Names)
So now Names =
corazona
Pebleo00
cofriasd
paflio
But, I am having trouble with the second regex that converts "Names" into the items of a sequence. I would like to convert "Names" into...
'corazona', 'Pebleo00', 'cofriasd', 'paflio'
or
'corazona', 'Pebleo00', 'cofriasd', 'paflio',
So sikuli can then recognize it as a List (I've found that Sikuli is able to recognize it even with those last "comma" and "space" in the end) by using...
NamesAsList = eval(Names)
How could I do this in python? is it necessary to use regex, or there is other way to do this in python?
I have already done this but using .Net regex, I just don't know how to do it in python, I have googled it with no result.
This is how I did it using .Net regex
Text to find:
(.*[^$])(\r\n|\z)
Replace with:
'$1',%" "%
Thanks Advanced.
A couple of one liners. Your question isn't completely clear - but I am assuming - you want to split a given string delimited by 'newline' and then generate a list of strings by removing the first character if it's not alpha numeric. Here's how I'd go about it
import re
r = re.compile(r'^[a-zA-Z0-9]') # match # beginning anything that's not alpha numeric
s = '#abc\ndef\nghi'
l = [r.sub('', x) for x in s.split()]
# join this list with comma (if that's required else you got the list already)
','.join(l)
Hope that's what you want.
If Names is a string before you "convert" it, in which each name is separated by a new line ('\n'), then this will work:
NamesAsList = '\n'.split(Names)
See this question for other options.
You could use splitlines()
import re
clipBoard = App.getClipboard();
Names = re.sub(r"(?m)^([^\x00-\x7F]+|\W|\d)", "", clipBoard)
# Replace the end of a line with a comma.
singleNames = ', '.join(Names.splitlines())
print(singleNames)
I have a string pa$$word. I want to change this string to pa\$\$word. This must be changed to 2 or more such characters only and not for pa$word. The replacement must happen n number of times where n is the number of "$" symbols. For example, pa$$$$word becomes pa\$\$\$\$word and pa$$$word becomes pa\$\$\$word.
How can I do it?
import re
def replacer(matchobj):
mat = matchobj.group()
return "".join(item for items in zip("\\" * len(mat), mat) for item in items)
print re.sub(r"((\$)\2+)", replacer, "pa$$$$word")
# pa\$\$\$\$word
print re.sub(r"((\$)\2+)", replacer, "pa$$$word")
# pa\$\$\$word
print re.sub(r"((\$)\2+)", replacer, "pa$$word")
# pa\$\$word
print re.sub(r"((\$)\2+)", replacer, "pa$word")
# pa$word
((\$)\2+) - We create two capturing groups here. First one is, the entire match as it is, which can be referred later as \1. The second capturing group is a nested one, which captures the string \$ and referred as \2. So, we first match $ once and make sure that it exists more than once, continuously by \2+.
So, when we find a string like that, we call replacer function with the matched string and the captured groups. In the replacer function, we get the entire matched string with matchobj.group() and then we simply interleave that matched string with \.
I believe the regex you're after is:
[$]{2,}
which will match 2 or more of the character $
this should help
import re
result = re.sub("\$", "\\$", yourString)
or you can try
str.replace("\$", "\\$")
i need to find and replace patterns in a string with a dynamically generated content.
lets say i want to find all strings within '' in the string and double the string.
a string like:
my 'cat' is 'white' should become my 'catcat' is 'whitewhite'
all matches could also appear twice in the string.
thank you
Make use of the power of regular expressions. In this particular case:
import re
s = "my 'cat' is 'white'"
print re.sub("'([^']+)'", r"'\1\1'", s) # prints my 'catcat' is 'whitewhite'
\1 refers to the first group in the regex (called $1 in some other implementations).
It's also pretty easy to do it without regex in your case:
s = "my 'cat' is 'white'".split("'")
# the parts between the ' are at the 1, 3, 5 .. index
print s[1::2]
# replace them with new elements
s[1::2] = [x+x for x in s[1::2]]
# join that stuff back together
print "'".join(s)