guys i hope you can give me a hand with this:
Im trying to find a match on a variable value:
net_card is a string
net_card = salida.read()
regex = re.compile('([a-z])\w+' % re.escape(net_card))
if i run this code it show me this error:
regex = re.compile('([a-z])\w+' % re.escape(net_card))
TypeError: not all arguments converted during string formatting
I haven't found a way to solve this, even with scape characters.
now if i do this:
net_card = salida.read()
match = re.search('([a-z])\w+', net_card)
whatIWant = match.group(1) if match else None
print whatIWant
it shows me just (e) in the output even when the value of net_card is NAME=ens32.
Your regex, ([a-z])\w+, will match a single character in the range a-z as the first group, and match the rest of the string as [a-zA-Z0-9_]+. Instead, match the two groups of \w+ (which is [a-zA-Z0-9_]+ in evaluation), separated by an equal sign. Here's an expression:
(\w+)=(\w+)
In practice (if you don't care about "NAME"), you can remove the first group and use:
net_card = salida.read()
match = re.match('\w+=(\w+)', net_card)
print(match.group(1) if match else None)
Which will output ens32.
Related
Given strings like:
"hello"
'hello'
I want to remove only first and last char if:
They are the same
They are " or '
I.e., given 'hello' I'm expecting hello. Given 'hello" I'm not expecting it to change.
I was able to do this by reading first char and last char, validating they are the same + validating they are equal to ' or " and validating it's not the the same index for char (because I don't want this: ' to end up as the empty string). With all edge cases checking I ended with 10s of lines.
What's your approach to solve this?
In simple words, Given a string in Python format I want to return its data and if it's not valid to keep it as is.
Sounds like a job for regular expressions with groups:
import re
re.sub(r'^([\'"])(.*)(\1)$', r'\2', s)
Which reads as:
^ - match the beginning of the string
(['"]) - either single or double quote (group 1)
(.*) any (possibly, empty) sequence of characters in between (group 2)
(\1) - the same character as in group 1
$ - end of the string
If the string matches the pattern above, replace it with the content of the group 2.
For example:
>>> s = re.sub(r'^([\'"])(.*)(\1)$', r'\2', "'hello'")
>>> print(s)
hello
An alternative way could be with ast.literal_eval(), but it won't handle non-matching quotes.
I would use str.endswith and str.startswith, although it still gets a bit long:
def readstring(string):
if len(string)>1 and (string.startswith('"') and string.endswith('"') or string.startswith("'") and string.endswith("'")):
return string[1:-1]
return string
I have a file with two different types of data I'd like to parse with a regex; however, the data is similar enough that I can't find the correct way to distinguish it.
Some lines in my file are of form:
AED=FRI
AFN=FRI:SAT
AMD=SUN:SAT
Other lines are of form
AED=20180823
AMD=20150914
AMD=20150921
The remaining lines are headers and I'd like to discard them. For example
[HEADER: BUSINESS DATE=20160831]
My solution attempt so far is to match first three capital letters and an equal sign,
r'\b[A-Z]{3}=\b'
but after that I'm not sure how to distinguish between dates (eg 20180823) and days (eg FRI:SAT:SUN).
The results I'd expect from these parsing functions:
Regex weekday_rx = new Regex(<EXPRESSION FOR TYPES LIKE AED=FRI>);
Regex date_rx = new Regex(<EXPRESSION FOR TYPES LIKE AED=20160816>);
weekdays = [weekday_rx.Match(line) for line in infile.read()]
dates = [date_rx.Match(line) for line in infile.read()]
r'\S*\d$'
Will match all non-whitespace characters that end in a digit
Will match AED=20180823
r'\S*[a-zA-Z]$'
Matches all non-whitespace characters that end in a letter.
will match AED=AED=FRI
AFN=FRI:SAT
AMD=SUN:SAT
Neither will match
[HEADER: BUSINESS DATE=20160831]
This will match both
r'(\S*[a-zA-Z]$|\S*\d$)'
Replacing the * with the number of occurences you expect will be safer, the (a|b) is match a or match b
The following is a solution in Python :)
import re
p = re.compile(r'\b([A-Z]{3})=((\d)+|([A-Z])+)')
str_test_01 = "AMD=SUN:SAT"
m = p.search(str_test_01)
print (m.group(1))
print (m.group(2))
str_test_02 = "AMD=20150921"
m = p.search(str_test_02)
print (m.group(1))
print (m.group(2))
"""
<Output>
AMD
SUN
AMD
20150921
"""
Use pipes to express alternatives in regex. Pattern '[A-Z]{3}:[A-Z]{3}|[A-Z]{3}' will match both ABC and ABC:ABC. Then use parenthesis to group results:
import re
match = re.match(r'([A-Z]{3}:[A-Z]{3})|([A-Z]{3})', 'ABC:ABC')
assert match.groups() == ('ABC:ABC', None)
match = re.match(r'([A-Z]{3}:[A-Z]{3})|([A-Z]{3})', 'ABC')
assert match.groups() == (None, 'ABC')
You can research the concept of named groups to make this even more readable. Also, take a look at the docs for the match object for useful info and methods.
I'm a newbie at python.
So my file has lines that look like this:
-1 1:-0.294118 2:0.487437 3:0.180328 4:-0.292929 5:-1 6:0.00149028 7:-0.53117 8:-0.0333333
I need help coming up with the correct python code to extract every float preceded by a colon and followed by a space (ex: [-0.294118, 0.487437,etc...])
I've tried dataList = re.findall(':(.\*) ', str(line)) and dataList = re.split(':(.\*) ', str(line)) but these come up with the whole line. I've been researching this problem for a while now so any help would be appreciated. Thanks!
try this one:
:(-?\d\.\d+)\s
In your code that will be
p = re.compile(':(-?\d\.\d+)\s')
m = p.match(str(line))
dataList = m.groups()
This is more specific on what you want.
In your case .* will match everything it can
Test on Regexr.com:
In this case last element wasn't captured because it doesnt have space to follow, if this is a problem just remove the \s from the regex
This will do it:
import re
line = "-1 1:-0.294118 2:0.487437 3:0.180328 4:-0.292929 5:-1 6:0.00149028 7:-0.53117 8:-0.0333333"
for match in re.finditer(r"(-?\d\.\d+)", line, re.DOTALL | re.MULTILINE):
print match.group(1)
Or:
match = re.search(r"(-?\d\.\d+)", line, re.DOTALL | re.MULTILINE)
if match:
datalist = match.group(1)
else:
datalist = ""
Output:
-0.294118
0.487437
0.180328
-0.292929
0.00149028
-0.53117
-0.0333333
Live Python Example:
http://ideone.com/DpiOBq
Regex Demo:
https://regex101.com/r/nR4wK9/3
Regex Explanation
(-?\d\.\d+)
Match the regex below and capture its match into backreference number 1 «(-?\d\.\d+)»
Match the character “-” literally «-?»
Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
Match a single character that is a “digit” (ASCII 0–9 only) «\d»
Match the character “.” literally «\.»
Match a single character that is a “digit” (ASCII 0–9 only) «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Given:
>>> s='-1 1:-0.294118 2:0.487437 3:0.180328 4:-0.292929 5:-1 6:0.00149028 7:-0.53117 8:-0.0333.333'
With your particular data example, you can just grab the parts that would be part of a float with a regex:
>>> re.findall(r':([\d.-]+)', s)
['-0.294118', '0.487437', '0.180328', '-0.292929', '-1', '0.00149028', '-0.53117', '-0.0333.333']
You can also split and partition, which would be substantially faster:
>>> [e.partition(':')[2] for e in s.split() if ':' in e]
['-0.294118', '0.487437', '0.180328', '-0.292929', '-1', '0.00149028', '-0.53117', '-0.0333.333']
Then you can convert those to a float using try/except and map and filter:
>>> def conv(s):
... try:
... return float(s)
... except ValueError:
... return None
...
>>> filter(None, map(conv, [e.partition(':')[2] for e in s.split() if ':' in e]))
[-0.294118, 0.487437, 0.180328, -0.292929, -1.0, 0.00149028, -0.53117, -0.0333333]
A simple oneliner using list comprehension -
str = "-1 1:-0.294118 2:0.487437 3:0.180328 4:-0.292929 5:-1 6:0.00149028 7:-0.53117 8:-0.0333333"
[float(s.split()[0]) for s in str.split(':')]
Note: this is simplest to understand (and pobably fastest) as we are not doing any regex evaluation. But this would only work for the particular case above. (eg. if you've to get the second number - in the above not so correctly formatted string would need more work than a single one-liner above).
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 want to parse a string, such as:
package: name='jp.tjkapp.droid1lwp' versionCode='2' versionName='1.1'
uses-permission:'android.permission.WRITE_APN_SETTINGS'
uses-permission:'android.permission.RECEIVE_BOOT_COMPLETED'
uses-permission:'android.permission.ACCESS_NETWORK_STATE'
I want to get:
string1: jp.tjkapp.droidllwp`
string2: 1.1
Because there are multiple uses-permission, I want to get permission as a list, contains:
WRITE_APN_SETTINGS, RECEIVE_BOOT_COMPLETED and ACCESS_NETWORK_STATE.
Could you help me write the python regular expression to get the strings I want?
Thanks.
Assuming the code block you provided is one long string, here stored in a variable called input_string:
name = re.search(r"(?<=name\=\')[\w\.]+?(?=\')", input_string).group(0)
versionName = re.search(r"(?<=versionName\=\')\d+?\.\d+?(?=\')", input_string).group(0)
permissions = re.findall(r'(?<=android\.permission\.)[A-Z_]+(?=\')', input_string)
Explanation:
name
(?<=name\=\'): check ahead of the main string in order to return only strings that are preceded by name='. The \ in front of = and ' serve to escape them so that the regex knows we're talking about the = string and not a regex command. name=' is not also returned when we get the result, we just know that the results we get are all preceded by it.
[\w\.]+?: This is the main string we're searching for. \w means any alphanumeric character and underscore. \. is an escaped period, so the regex knows we mean . and not the regex command represented by an unescaped period. Putting these in [] means we're okay with anything we've stuck in brackets, so we're saying that we'll accept any alphanumeric character, _, or .. + afterwords means at least one of the previous thing, meaning at least one (but possibly more) of [\w\.]. Finally, the ? means don't be greedy--we're telling the regex to get the smallest possible group that meets these specifications, since + could go on for an unlimited number of repeats of anything matched by [\w\.].
(?=\'): check behind the main string in order to return only strings that are followed by '. The \ is also an escape, since otherwise regex or Python's string execution might misinterpret '. This final ' is not returned with our results, we just know that in the original string, it followed any result we do end up getting.
You can do this without regex by reading the file content line by line.
>>> def split_string(s):
... if s.startswith('package'):
... return [i.split('=')[1] for i in s.split() if "=" in i]
... elif s.startswith('uses-permission'):
... return s.split('.')[-1]
...
>>> split_string("package: name='jp.tjkapp.droid1lwp' versionCode='2' versionName='1.1'")
["'jp.tjkapp.droid1lwp'", "'2'", "'1.1'"]
>>> split_string("uses-permission:'android.permission.WRITE_APN_SETTINGS'")
"WRITE_APN_SETTINGS'"
>>> split_string("uses-permission:'android.permission.RECEIVE_BOOT_COMPLETED'")
"RECEIVE_BOOT_COMPLETED'"
>>> split_string("uses-permission:'android.permission.ACCESS_NETWORK_STATE'")
"ACCESS_NETWORK_STATE'"
>>>
Here is one example code
#!/usr/bin/env python
inputFile = open("test.txt", "r").readlines()
for line in inputFile:
if line.startswith("package"):
words = line.split()
string1 = words[1].split("=")[1].replace("'","")
string2 = words[3].split("=")[1].replace("'","")
test.txt file contains input data you mentioned earlier..