I need to identify where some powershell path strings cross over into Python.
How do I detect if a path in Python starts with .\ ??
Here's an example:
import re
file_path = ".\reports\dsReports"
if re.match(r'.\\', file_path):
print "Pass"
else:
print "Fail"
This Fails, in the debugger it lists
expression = .\\\\\\
string = .\\reports\\\\dsReports
If I try using replace like so:
import re
file_path = ".\reports\dsReports"
testThis = file_path.replace(r'\', '&jkl$ff88')
if re.match(r'.&jkl$ff88', file_path):
print "Pass"
else:
print "Fail"
the testThis variable ends up like this:
testThis = '.\\reports&jkl$ff88dsReports'
Quite agravating.
The reason this is happening is because \r is an escape sequence. You will need to either escape the backslashes by doubling them, or use a raw string literal like this:
file_path = r".\reports\dsReports"
And then check if it starts with ".\\":
if file_path.startswith('.\\'):
do_whatever()
Related
So I am reading and manipulate a file with :
base_file = open(path+'/'+base_name, "r")
lines = base_file.readlines()
After this I search and find the "raw_data" start of line.
if re.match("\s{0,100}raw_data: ",line):
split_line = line.split("raw_data:")
print(split_line)
raw_string = split_line[1]
One example of raw_data is:
raw_data: "&\276!\300\307 =\277\"O\271\277vH9?j?\345?#\243\264=\350\034\345\277\260\345\033\300\023\017(#z|\273\277L\}\277\210\\031\300\213\263z\277\302\241\033\300\000\207\323\277\247Oh>j\354\215#\364\305\201\276\361+\202#t:\304\277\344\231\243#\225k\002\300vw\262\277\362\220j\300\"(\337\276\354b8\300\230\347H\300\201\320\204\300S;N\300Z0G\300>j\210\000#\034\014\220#\231\330J#\223\025\236#\006\332\230\276\227\273\n\277\353#,#\202\205\215\277\340\356\022\300/\223\035\277\331\277\362\276a\350\013#)\353\276\277v6\316\277K\326\207\300`2)\300\004\014Q\300\340\267\271\300MV\305\300\327\010\207\300j\346o\300\377\260\216\300[\332g\300\336\266\003\300\320S\272?6\300Y#\356\250\034\300\367\277&\300\335Uq>o\010&\300r\277\252\300U\314\243\300\253d\377\300"
And raw_string will be
print(raw_data)
"&\276!\300\307
=\277\"O\271\277vH9?j?\345?#\243\264=\350\034\345\277\260\345\033\300\023\017(#z|\273\277L\}\277\210\\031\300\213\263z\277\302\241\033\300\000\207\323\277\247Oh>j\354\215#\364\305\201\276\361+\202#t:\304\277\344\231\243#\225k\002\300vw\262\277\362\220j\300\"(\337\276\354b8\300\230\347H\300\201\320\204\300S;N\300Z0G\300>j\210\000#\034\014\220#\231\330J#\223\025\236#\006\332\230\276\227\273\n\277\353#,#\202\205\215\277\340\356\022\300/\223\035\277\331\277\362\276a\350\013#)\353\276\277v6\316\277K\326\207\300`2)\300\004\014Q\300\340\267\271\300MV\305\300\327\010\207\300j\346o\300\377\260\216\300[\332g\300\336\266\003\300\320S\272?6\300Y#\356\250\034\300\367\277&\300\335Uq>o\010&\300r\277\252\300U\314\243\300\253d\377\300"
If I tried to read this file I will obtain one char to one char even for escape characters.
So, my question is how to transform this plain text to utf-8 string so that I can have one character when reading \300 and not 4 characters.
I tried to pass "encondig =utf-8" in open file method but does not work.
I have made the same example passing raw_data as variable and it works properly.
RAW_DATA = "&\276!\300\307 =\277\"O\271\277vH9?j?\345?#\243\264=\350\034\345\277\260\345\033\300\023\017(#z|\273\277L\\}\277\210\\\031\300\213\263z\277\302\241\033\300\000\207\323\277\247Oh>j\354\215#\364\305\201\276\361+\202#t:\304\277\344\231\243#\225k\002\300vw\262\277\362\220j\300\"(\337\276\354b8\300\230\347H\300\201\320\204\300S;N\300Z0G\300<I>>j\210\000#\034\014\220#\231\330J#\223\025\236#\006\332\230\276\227\273\n\277\353#,#\202\205\215\277\340\356\022\300/\223\035\277\331\277\362\276a\350\013#)\353\276\277v6\316\277K\326\207\300`2)\300\004\014Q\300\340\267\271\300MV\305\300\327\010\207\300j\346o\300\377\260\216\300[\332g\300\336\266\003\300\320S\272?6\300Y#\356\250\034\300\367\277&\300\335Uq>o\010&\300r\277\252\300U\314\243\300\253d\377\300"
print(f"Qnt -> {len(RAW_DATA)}") # Qnt -> 256
print(type(RAW_DATA))
at = 0
total = 0
while at < len(RAW_DATA):
fin = at+4
substrin = RAW_DATA[at:fin]
resu = FourString_float(substrin)
at = fin
For this example \300 is only one char.
Hope someone can help me.
The problem is that on the read file the escape \ symbols are coming in as \, but in the example you've provided they are being evaluated as part of the numerics that follow it. ie, \276 is read as a single character.
If you run:
RAW_DATA = r"&\276!\300\307 =\277\"O\271\277vH9?j?\345?#\243\264=\350\034\345\277\260\345\033\300\023\017(#z|\273\277L\\}\277\210\\\031\300\213\263z\277\302\241\033\300\000\207\323\277\247Oh>j\354\215#\364\305\201\276\361+\202#t:\304\277\344\231\243#\225k\002\300vw\262\277\362\220j\300\"(\337\276\354b8\300\230\347H\300\201\320\204\300S;N\300Z0G\300<I>>j\210\000#\034\014\220#\231\330J#\223\025\236#\006\332\230\276\227\273\n\277\353#,#\202\205\215\277\340\356\022\300/\223\035\277\331\277\362\276a\350\013#)\353\276\277v6\316\277K\326\207\300`2)\300\004\014Q\300\340\267\271\300MV\305\300\327\010\207\300j\346o\300\377\260\216\300[\332g\300\336\266\003\300\320S\272?6\300Y#\356\250\034\300\367\277&\300\335Uq>o\010&\300r\277\252\300U\314\243\300\253d\377\300"
print(f"Qnt -> {len(RAW_DATA)}") # Qnt -> 256
print(type(RAW_DATA))
at = 0
total = 0
while at < len(RAW_DATA):
fin = at+4
substrin = RAW_DATA[at:fin]
resu = FourString_float(substrin)
at = fin
You would should be getting the same error that you were getting originally. Notice that we are using the raw-string literal instead of regular string literal. This will ensure that the \ don't get escaped.
You would need to evaluate the RAW_DATA to force it to evaluate the \.
You can do something like RAW_DATA = eval(f'"{RAW_DATA}"') or
import ast
RAW_DATA = ast.literal_eval(f'"{RAW_DATA}"')
Note, the second option is a bit more secure that doing a straight eval as you are limiting the scope of what can be executed.
import os.path
import re
def request ():
print ("What file should I write to?")
file = input ()
thing = os.path.exists (file)
if thing == True:
start = 0
elif re.match ("^.+.\txt$", file):
stuff = open (file, "w")
stuff.write ("Some text.")
stuff.close ()
start = 0
else:
start = 1
go = "yes"
list1 = (start, file, go)
return list1
start = 1
while start == 1:
list1 = request ()
(start, file, go) = list1
Whenever I enter Thing.txt as the text, the elif should catch that it's in the format given. However, start doesn't change to 0, and a file isn't created. Have I formatted the re.match incorrectly?
"^.+.\txt$" is an incorrect pattern for match .txt files you can use the following regex :
r'^\w+\.txt$'
As \w matches word character if you want that the file name only contain letters you could use [a-zA-Z] instead :
r'^[a-zA-Z]+\.txt$'
Note that you need to escape the . as is a special sign in regular expression .
re.match (r'^\w+\.txt$',file)
But as an alternative answer for match file names with special format you can use endswith() :
file.endswith('.txt')
Also instead of if thing == True you can just use if thing : that is more pythonic !
You should escape second dot and unescape the "t" character:
re.match ("^.+\.txt$", file)
Also note that you don't really need regex for this, you can simply use endswith or search for module that can give you files extensions:
import os
fileName, fileExtension = os.path.splitext('your_file.txt')
fileExtension is .txt, which is exactly what you're looking for.
I am trying to get the index for the start of a tag and the end of another tag. However, when I use one regex it works absolutely fine but for two regex functions, it gives an error for the second one.
Kindly help in explaining the reason
The below code works fine:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
opentag = re.search('<TEXT>',f.read())
begin = opentag.start()+6
print begin
But when I add another similar regex it give me the error
AttributeError: 'NoneType' object has no attribute 'start'
which I understand is due to the start() function returning None
Below is the code:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
opentag = re.search('<TEXT>',f.read())
begin = opentag.start()+6
print begin
closetag = re.search('</TEXT>',f.read())
end = closetag.start() - 1
print end
Please provide a solution to how can I get this working. Also I am a newbie here so please don't mind if I ask more questions on the solution.
You are reading the file in f.read() which reads the whole file, and so the file descriptor moves forward, which means the text can't be read again when you do f.read() the next time.
If you need to search on the same text again, save the output of f.read(), and then do a regular expression search on it as below:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
text = f.read()
opentag = re.search('<TEXT>',text)
begin = opentag.start()+6
print begin
closetag = re.search('</TEXT>',text)
end = closetag.start() - 1
print end
f.read() reads the whole file. So there's nothing left to read on the second f.read() call.
See https://docs.python.org/2/tutorial/inputoutput.html#methods-of-file-objects
First of all you have to know that f.read() after read file sets the pointer to the EOF so if you again use f.read() it gives you empty string ''. Secondly you should use r before string passed as a pattern of re.search function, which means raw, and automatically escapes special characters. So you have to do something like this:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
data = f.read()
opentag = re.search(r'<TEXT>',data)
begin = opentag.start()+6
print begin
closetag = re.search(r'</TEXT>',data)
end = closetag.start() - 1
print end
gl & hf with Python :)
I have the following python script:
import sys
import io
str1 = 'asd'
str2 - 'asd'
if (str2.find(str1)==-1):
print('FALSE')
else:
print('TRUE')
#Prints "TRUE"
It works fine. No problem. The problem starts if I take the string, put it in a file (save it) and then read the content of the file to str1 and str2, like so:
import sys
import io
fHandler = open(r'C:\dev\1.pub','r')
str1 = fHandler.read()
str2 = fHandler.read()
if (str2.find(str1)==-1):
print('FALSE')
else:
print('TRUE')
#Prints "FALSE"
Why is the behaviour different?
Thanks!
If you try to call fHandler.read() twice, then the second one will return n empty string (or empty bytes if you read binary). fHandler.read() reads everything until the end and the second call will start reading at the end until the end, so it returns an empty string. Try adding fHandler.seek(0) beetween your function calls and it should work.
i have below code in which filenames are FR1.1.csv, FR2.0.csv etc. I am using these names to print in header row but i want to modify these name to FR1.1 , Fr2.0 and so on. Hence i am using strip function to remove .csv. when i have tried it at command prompt its working fine. But when i have added it to main script its not giving output.
for fname in filenames:
print "fname : ", fname
fname.strip('.csv');
print "after strip fname: ", fname
headerline.append(fname+' Compile');
headerline.append(fname+' Run');
output i am getting
fname :FR1.1.csv
after strip fname: FR1.1.csv
required output-->
fname :FR1.1.csv
after strip fname: FR1.1
i guess some indentation problem is there in my code after for loop.
plesae tell me what is the correct way to achive this.
Strings are immutable, so string methods can't change the original string, they return a new one which you need to assign again:
fname = fname.strip('.csv') # no semicolons in Python!
But this call doesn't do what you probably expect it to. It will remove all the leading and trailing characters c, s, v and . from your string:
>>> "cross.csv".strip(".csv")
'ro'
So you probably want to do
import re
fname = re.sub(r"\.csv$", "", fname)
Strings are immutable. strip() returns a new string.
>>> "FR1.1.csv".strip('.csv')
'FR1.1'
>>> m = "FR1.1.csv".strip('.csv')
>>> print(m)
FR1.1
You need to do fname = fname.strip('.csv').
And get rid of the semicolons in the end!
P.S - Please see Jon Clement's comment and Tim Pietzcker's answer to know why this code should not be used.
You probably should use os.path for path manipulations:
import os
#...
for fname in filenames:
print "fname : ", fname
fname = os.path.splitext(fname)[0]
#...
The particular reason why your code fails is provided in other answers.
change
fname.strip('.csv')
with
fname = fname.strip('.csv')