String Delimiter in Python - python

I want to do split a string using "},{" as the delimiter. I have tried various things but none of them work.
string="2,1,6,4,5,1},{8,1,4,9,6,6,7,0},{6,1,2,3,9},{2,3,5,4,3 "
Split it into something like this:
2,1,6,4,5,1
8,1,4,9,6,6,7,0
6,1,2,3,9
2,3,5,4,3
string.split("},{") works at the Python console but if I write a Python script in which do this operation it does not work.

You need to assign the result of string.split("},{") to a new string. For example:
string2 = string.split("},{")
I think that is the reason you think it works at the console but not in scripts. In the console it just prints out the return value, but in the script you want to make sure you use the returned value.

You need to return the string back to the caller. Assigning to the string parameter doesn't change the caller's variable, so those changes are lost.
def convert2list(string):
string = string.strip()
string = string[2:len(string)-2].split("},{")
# Return to caller.
return string
# Grab return value.
converted = convert2list("{1,2},{3,4}")

You could do it in steps:
Split at commas to get "{...}" strings.
Remove leading and trailing curly braces.
It might not be the most Pythonic or efficient, but it's general and doable.

I was taking the input from the console in the form of arguments to the script....
So when I was taking the input as {{2,4,5},{1,9,4,8,6,6,7},{1,2,3},{2,3}} it was not coming properly in the arg[1] .. so the split was basically splitting on an empty string ...

If I run the below code from a script file (in Python 2.7):
string="2,1,6,4,5,1},{8,1,4,9,6,6,7,0},{6,1,2,3,9},{2,3,5,4,3 "
print string.split("},{")
Then the output I got is:
['2,1,6,4,5,1', '8,1,4,9,6,6,7,0', '6,1,2,3,9', '2,3,5,4,3 ']
And the below code also works fine:
string="2,1,6,4,5,1},{8,1,4,9,6,6,7,0},{6,1,2,3,9},{2,3,5,4,3 "
def convert2list(string):
string=string.strip()
string=string[:len(string)].split("},{")
print string
convert2list(string)

Use This:
This will split the string considering },{ as a delimiter and print the list with line breaks.
string = "2,1,6,4,5,1},{8,1,4,9,6,6,7,0},{6,1,2,3,9},{2,3,5,4,3"
for each in string.split('},{'):
print each
Output:
2,1,6,4,5,1
8,1,4,9,6,6,7,0
6,1,2,3,9
2,3,5,4,3
If you want to print the split items in the list only you can use this simple print option.
string = "2,1,6,4,5,1},{8,1,4,9,6,6,7,0},{6,1,2,3,9},{2,3,5,4,3"
print string.split('},{')
Output:
['2,1,6,4,5,1', '8,1,4,9,6,6,7,0', '6,1,2,3,9', '2,3,5,4,3']

Quite simply ,you have to use split() method ,and "},{" as a delimeter, then print according to arguments (because string will be a list ) ,
like the following :
string.split("},{")
for i in range(0,len(string)):
print(string[i])

Related

How to convert a regular string to a raw string? [duplicate]

I have a string s, its contents are variable. How can I make it a raw string? I'm looking for something similar to the r'' method.
i believe what you're looking for is the str.encode("string-escape") function. For example, if you have a variable that you want to 'raw string':
a = '\x89'
a.encode('unicode_escape')
'\\x89'
Note: Use string-escape for python 2.x and older versions
I was searching for a similar solution and found the solution via:
casting raw strings python
Raw strings are not a different kind of string. They are a different way of describing a string in your source code. Once the string is created, it is what it is.
Since strings in Python are immutable, you cannot "make it" anything different. You can however, create a new raw string from s, like this:
raw_s = r'{}'.format(s)
As of Python 3.6, you can use the following (similar to #slashCoder):
def to_raw(string):
return fr"{string}"
my_dir ="C:\data\projects"
to_raw(my_dir)
yields 'C:\\data\\projects'. I'm using it on a Windows 10 machine to pass directories to functions.
raw strings apply only to string literals. they exist so that you can more conveniently express strings that would be modified by escape sequence processing. This is most especially useful when writing out regular expressions, or other forms of code in string literals. if you want a unicode string without escape processing, just prefix it with ur, like ur'somestring'.
For Python 3, the way to do this that doesn't add double backslashes and simply preserves \n, \t, etc. is:
a = 'hello\nbobby\nsally\n'
a.encode('unicode-escape').decode().replace('\\\\', '\\')
print(a)
Which gives a value that can be written as CSV:
hello\nbobby\nsally\n
There doesn't seem to be a solution for other special characters, however, that may get a single \ before them. It's a bummer. Solving that would be complex.
For example, to serialize a pandas.Series containing a list of strings with special characters in to a textfile in the format BERT expects with a CR between each sentence and a blank line between each document:
with open('sentences.csv', 'w') as f:
current_idx = 0
for idx, doc in sentences.items():
# Insert a newline to separate documents
if idx != current_idx:
f.write('\n')
# Write each sentence exactly as it appared to one line each
for sentence in doc:
f.write(sentence.encode('unicode-escape').decode().replace('\\\\', '\\') + '\n')
This outputs (for the Github CodeSearchNet docstrings for all languages tokenized into sentences):
Makes sure the fast-path emits in order.
#param value the value to emit or queue up\n#param delayError if true, errors are delayed until the source has terminated\n#param disposable the resource to dispose if the drain terminates
Mirrors the one ObservableSource in an Iterable of several ObservableSources that first either emits an item or sends\na termination notification.
Scheduler:\n{#code amb} does not operate by default on a particular {#link Scheduler}.
#param the common element type\n#param sources\nan Iterable of ObservableSource sources competing to react first.
A subscription to each source will\noccur in the same order as in the Iterable.
#return an Observable that emits the same sequence as whichever of the source ObservableSources first\nemitted an item or sent a termination notification\n#see ReactiveX operators documentation: Amb
...
Just format like that:
s = "your string"; raw_s = r'{0}'.format(s)
With a little bit correcting #Jolly1234's Answer:
here is the code:
raw_string=path.encode('unicode_escape').decode()
s = "hel\nlo"
raws = '%r'%s #coversion to raw string
#print(raws) will print 'hel\nlo' with single quotes.
print(raws[1:-1]) # will print hel\nlo without single quotes.
#raws[1:-1] string slicing is performed
The solution, which worked for me was:
fr"{orignal_string}"
Suggested in comments by #ChemEnger
I suppose repr function can help you:
s = 't\n'
repr(s)
"'t\\n'"
repr(s)[1:-1]
't\\n'
Just simply use the encode function.
my_var = 'hello'
my_var_bytes = my_var.encode()
print(my_var_bytes)
And then to convert it back to a regular string do this
my_var_bytes = 'hello'
my_var = my_var_bytes.decode()
print(my_var)
--EDIT--
The following does not make the string raw but instead encodes it to bytes and decodes it.

Can't replace a string with multiple escape characters

I am having trouble with the replace() method. I want to replace some part of a string, and the part which I want to replace consist of multiple escape characters. It looks like something like this;
['<div class=\"content\">rn
To remove it, I have a block of code;
garbage_text = "[\'<div class=\\\"content\\\">rn "
entry = entry.replace(garbage_text,"")
However, it does not work. Anything is removed from my complete string. Can anybody point out where exactly I am thinking wrong about it? Thanks in advance.
Addition:
The complete string looks like this;
"['<div class=\"content\">rn gitar calmak icin kullanilan minik plastik garip nesne.rn </div>']"
You could use the triple quote format for your replacement string so that you don't have to bother with escaping at all:
garbage_text = """['<div class="content">rn """
Perhaps your 'entry' is not formatted correctly?
With an extra variable 'text', the following worked in Python 3.6.7:
>>> garbage_text
'[\'<div class=\\\'content\'\\">rn '
>>> text
'[\'<div class=\\\'content\'\\">rn And then there were none'
>>> entry = text.replace(garbage_text, "")
>>> entry
'And then there were none'

Python - \n appearing in concatenated strings

I've been having an issue with my Python code. I am trying to concatenate the value of two string objects, but when I run the code it keeps printing a '\n' between the two strings.
My code:
while i < len(valList):
curVal = valList[i]
print(curVal)
markupConstant = 'markup.txt'
markupFileName = curVal + markupConstant
markupFile = open(markupFileName)
Now when I run this, it gives me this error:
OSError: [Errno 22] Invalid argument: 'cornWhiteTrimmed\nmarkup.txt'
See that \n between the two strings? I've dissected the code a bit by printing each string individually, and neither one contains a \n on its own. Any ideas as to what I'm doing wrong?
Thanks in advance!
The concatenation itself doesn't add the \n for sure. valList is probably the result of calling readlines() on a file object, so each element in it will have a trailing \n. Call strip on each element before using it:
while i < len(valList):
curVal = valList[i].strip()
print(curVal)
markupConstant = 'markup.txt'
markupFileName = curVal + markupConstant
markupFile = open(markupFileName)
The reason you are not seeing the \n when you actually print out the python statements is because \n is technically the newline character. You will not see this when you actually print, it will only skip to a new line. The problem is when you have this in the middle of your two strings, it is going to cause problems. The solution to your issue is the strip method. You can read into its documentation here (https://www.tutorialspoint.com/python/string_strip.htm) but basically you can use this method to strip the newline character off of any of your strings.
Just to make an addition to the other answers explaining why this came about:
When you need to actually inspect what characters a string contains, you can't simply print it. Many characters are "invisible" when printed.
Turn the string into a list first:
list(curVal)
Or my personal favorite:
[c for c in curVal]
These will create lists that properly show all hard to see characters.

Python pass print statement including non strings to function

I'm trying to generate a log class which has a function that takes input and prints it to a log file. When printing to the console an example can be:
print("hi",[1,2,3])
which results in
hi [1,2,3]
However I have a function:
def printLog(input):
self.file.write('%s\n' % input)
However, passing this combination wouldn't work right. Is there someway I can pass "hi, [1,2,3]" as a string. This would have to convert the list to be printed exactly as it is printed in the console screen? This should deal with all data types, not just lists.
Use the file argument of print() function:
def printLog(*inp):
print(*inp, file=self.file)
You need to build the string yourself. The print statement (and function, when available) automatically calls str on each of its arguments, then prints them separated (by default) by a space.
def printLog(*input):
self.file.write('%s\n' % (" ".join(str(x) for x in input),))
how bout
print("A",[1,2,3],file=self.file)
Well, if I'm not mistaken, couldn't you just typecast the input into a string using str() right after you define printLog?
def printLog(input):
input = str(input)
self.file.write('%s\n' % input)

How to remove double quotes from strings in a list in python?

I am trying to get some data in a list of dictionaries.
The data comes from a csv file so it's all string.
the the keys in the file all have double qoutes, but since these are all strings, I want to remove them so they look like this in the dictionary:
{'key':value}
instead of this
{'"key"':value}
I tried simply using string = string[1:-1], but this doesn's work...
Here is my code:
csvDelimiter = ","
tsvDelimiter = "\t"
dataOutput = []
dataFile = open("browser-ww-monthly-201305-201405.csv","r")
for line in dataFile:
line = line[:-1] # Removes \n after every line
data = line.split(csvDelimiter)
for i in data:
if type(i) == str: # Doesn't work, I also tried if isinstance(i, str)
# but that didn't work either.
print i
i = i[1:-1]
print i
dataOutput.append({data[0] : data[1]})
dataFile.close()
print "Data output:\n"
print dataOutput
all the prints I get from print i are good, without double quotes, but when I append data to dataOutput, the quotes are back!
Any idea how to make them disappear forever?
Strip it. For example:
data[0].strip('"')
However, when reading cvs files, the best is to use the built-in cvs module. It takes care of this for you.
As noted in the comments, when dealing with CSV files you truly ought to use Python's built-in csv module (linking to Python 2 docs since it seems that's what you're using).
Another thing to note is that when you do:
data = line.split(csvDelimiter)
every item in the returned list, if it is not empty, will be strings. There's no sense in doing a type check in the loop (though if there were a reason to you would use isinstance). I don't know what "didn't work" about it, though it's possible you were using unicode strings. On Python 2 you can usually use isinstance(..., basestring) where basestring is a base class for both str and unicode. On Python 3 just use str unless you know you're dealing with bytes.
You said: "I tried simply using string = string[1:-1], but this doesn't work...". It seems to work fine for me:
In [101]: s="'word'"
In [102]: s[1:-1]
Out[102]: 'word'

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