Related
I want to check whether the given string is single- or double-quoted. If it is single quote I want to convert it to be double quote, else it has to be same double quote.
There is no difference between "single quoted" and "double quoted" strings in Python:
both are parsed internally to string objects.
I mean:
a = "European Swallow"
b = 'African Swallow'
Are internally string objects.
However you might mean to add an extra quote inside an string object, so that the content itself show up quoted when printed/exported?
c = "'Unladen Swallow'"
If you have a mix of quotes inside a string like:
a = """ Merry "Christmas"! Happy 'new year'! """
Then you can use the "replace" method to convert then all into one type:
a = a.replace('"', "'")
If you happen to have nested strings, then replace first the existing quotes to escaped quotes, and later the otuer quotes:
a = """This is an example: "containing 'nested' strings" """
a = a.replace("'", "\\\'")
a = a.replace('"', "'")
Sounds like you are working with JSON. I would just make sure it is always a double quoted like this:
doubleQString = "{0}".format('my normal string')
with open('sampledict.json','w') as f:
json.dump(doubleQString ,f)
Notice I'm using dump, not dumps.
Sampledict.json will look like this:
"my normal string"
In my case I needed to print list in json format.
This worked for me:
f'''"inputs" : {str(vec).replace("'", '"')},\n'''
Output:
"inputs" : ["Input_Vector0_0_0", "Input_Vector0_0_1"],
Before without replace:
f'"inputs" : {vec},\n'
"inputs" : ['Input_Vector0_0_0', 'Input_Vector0_0_1'],
The difference is only on input. They are the same.
s = "hi"
t = 'hi'
s == t
True
You can even do:
"hi" == 'hi'
True
Providing both methods is useful because you can for example have your string contain either ' or " directly without escaping.
In Python, there is no difference between strings that are single or double quoted, so I don't know why you would want to do this. However, if you actually mean single quote characters inside a string, then to replace them with double quotes, you would do this: mystring.replace('\'', '"')
Actually, none of the answers above as far as I know answers the question, the question how to convert a single quoted string to a double quoted one, regardless if for python is interchangeable one can be using Python to autogenerate code where is not.
One example can be trying to generate a SQL statement where which quotes are used can be very important, and furthermore a simple replace between double quote and single quote may not be so simple (i.e., you may have double quotes enclosed in single quotes).
print('INSERT INTO xx.xx VALUES' + str(tuple(['a',"b'c",'dfg'])) +';')
Which returns:
INSERT INTO xx.xx VALUES('a', "b'c", 'dfg');
At the moment I do not have a clear answer for this particular question but I thought worth pointing out in case someone knows. (Will come back if I figure it out though)
If you're talking about converting quotes inside a string, One thing you could do is replace single quotes with double quotes in the resulting string and use that. Something like this:
def toDouble(stmt):
return stmt.replace("'",'"')
I'm trying to find a way to print a string in raw form from a variable. For instance, if I add an environment variable to Windows for a path, which might look like 'C:\\Windows\Users\alexb\', I know I can do:
print(r'C:\\Windows\Users\alexb\')
But I cant put an r in front of a variable.... for instance:
test = 'C:\\Windows\Users\alexb\'
print(rtest)
Clearly would just try to print rtest.
I also know there's
test = 'C:\\Windows\Users\alexb\'
print(repr(test))
But this returns 'C:\\Windows\\Users\x07lexb'
as does
test = 'C:\\Windows\Users\alexb\'
print(test.encode('string-escape'))
So I'm wondering if there's any elegant way to make a variable holding that path print RAW, still using test? It would be nice if it was just
print(raw(test))
But its not
I had a similar problem and stumbled upon this question, and know thanks to Nick Olson-Harris' answer that the solution lies with changing the string.
Two ways of solving it:
Get the path you want using native python functions, e.g.:
test = os.getcwd() # In case the path in question is your current directory
print(repr(test))
This makes it platform independent and it now works with .encode. If this is an option for you, it's the more elegant solution.
If your string is not a path, define it in a way compatible with python strings, in this case by escaping your backslashes:
test = 'C:\\Windows\\Users\\alexb\\'
print(repr(test))
In general, to make a raw string out of a string variable, I use this:
string = "C:\\Windows\Users\alexb"
raw_string = r"{}".format(string)
output:
'C:\\\\Windows\\Users\\alexb'
You can't turn an existing string "raw". The r prefix on literals is understood by the parser; it tells it to ignore escape sequences in the string. However, once a string literal has been parsed, there's no difference between a raw string and a "regular" one. If you have a string that contains a newline, for instance, there's no way to tell at runtime whether that newline came from the escape sequence \n, from a literal newline in a triple-quoted string (perhaps even a raw one!), from calling chr(10), by reading it from a file, or whatever else you might be able to come up with. The actual string object constructed from any of those methods looks the same.
I know i'm too late for the answer but for people reading this I found a much easier way for doing it
myVariable = 'This string is supposed to be raw \'
print(r'%s' %myVariable)
try this. Based on what type of output you want. sometime you may not need single quote around printed string.
test = "qweqwe\n1212as\t121\\2asas"
print(repr(test)) # output: 'qweqwe\n1212as\t121\\2asas'
print( repr(test).strip("'")) # output: qweqwe\n1212as\t121\\2asas
Get rid of the escape characters before storing or manipulating the raw string:
You could change any backslashes of the path '\' to forward slashes '/' before storing them in a variable. The forward slashes don't need to be escaped:
>>> mypath = os.getcwd().replace('\\','/')
>>> os.path.exists(mypath)
True
>>>
Just simply use r'string'. Hope this will help you as I see you haven't got your expected answer yet:
test = 'C:\\Windows\Users\alexb\'
rawtest = r'%s' %test
I have my variable assigned to big complex pattern string for using with re module and it is concatenated with few other strings and in the end I want to print it then copy and check on regex101.com.
But when I print it in the interactive mode I get double slash - '\\w'
as #Jimmynoarms said:
The Solution for python 3x:
print(r'%s' % your_variable_pattern_str)
Your particular string won't work as typed because of the escape characters at the end \", won't allow it to close on the quotation.
Maybe I'm just wrong on that one because I'm still very new to python so if so please correct me but, changing it slightly to adjust for that, the repr() function will do the job of reproducing any string stored in a variable as a raw string.
You can do it two ways:
>>>print("C:\\Windows\Users\alexb\\")
C:\Windows\Users\alexb\
>>>print(r"C:\\Windows\Users\alexb\\")
C:\\Windows\Users\alexb\\
Store it in a variable:
test = "C:\\Windows\Users\alexb\\"
Use repr():
>>>print(repr(test))
'C:\\Windows\Users\alexb\\'
or string replacement with %r
print("%r" %test)
'C:\\Windows\Users\alexb\\'
The string will be reproduced with single quotes though so you would need to strip those off afterwards.
To turn a variable to raw str, just use
rf"{var}"
r is raw and f is f-str; put them together and boom it works.
Replace back-slash with forward-slash using one of the below:
re.sub(r"\", "/", x)
re.sub(r"\", "/", x)
This does the trick
>>> repr(string)[1:-1]
Here is the proof
>>> repr("\n")[1:-1] == r"\n"
True
And it can be easily extrapolated into a function if need be
>>> raw = lambda string: repr(string)[1:-1]
>>> raw("\n")
'\\n'
i wrote a small function.. but works for me
def conv(strng):
k=strng
k=k.replace('\a','\\a')
k=k.replace('\b','\\b')
k=k.replace('\f','\\f')
k=k.replace('\n','\\n')
k=k.replace('\r','\\r')
k=k.replace('\t','\\t')
k=k.replace('\v','\\v')
return k
Here is a straightforward solution.
address = 'C:\Windows\Users\local'
directory ="r'"+ address +"'"
print(directory)
"r'C:\\Windows\\Users\\local'"
Is there a way to declare a string variable in Python such that everything inside of it is automatically escaped, or has its literal character value?
I'm not asking how to escape the quotes with slashes, that's obvious. What I'm asking for is a general purpose way for making everything in a string literal so that I don't have to manually go through and escape everything for very large strings.
Raw string literals:
>>> r'abc\dev\t'
'abc\\dev\\t'
If you're dealing with very large strings, specifically multiline strings, be aware of the triple-quote syntax:
a = r"""This is a multiline string
with more than one line
in the source code."""
There is no such thing. It looks like you want something like "here documents" in Perl and the shells, but Python doesn't have that.
Using raw strings or multiline strings only means that there are fewer things to worry about. If you use a raw string then you still have to work around a terminal "\" and with any string solution you'll have to worry about the closing ", ', ''' or """ if it is included in your data.
That is, there's no way to have the string
' ''' """ " \
properly stored in any Python string literal without internal escaping of some sort.
You will find Python's string literal documentation here:
http://docs.python.org/tutorial/introduction.html#strings
and here:
http://docs.python.org/reference/lexical_analysis.html#literals
The simplest example would be using the 'r' prefix:
ss = r'Hello\nWorld'
print(ss)
Hello\nWorld
(Assuming you are not required to input the string from directly within Python code)
to get around the Issue Andrew Dalke pointed out, simply type the literal string into a text file and then use this;
input_ = '/directory_of_text_file/your_text_file.txt'
input_open = open(input_,'r+')
input_string = input_open.read()
print input_string
This will print the literal text of whatever is in the text file, even if it is;
' ''' """ “ \
Not fun or optimal, but can be useful, especially if you have 3 pages of code that would’ve needed character escaping.
Use print and repr:
>>> s = '\tgherkin\n'
>>> s
'\tgherkin\n'
>>> print(s)
gherkin
>>> repr(s)
"'\\tgherkin\\n'"
# print(repr(..)) gets literal
>>> print(repr(s))
'\tgherkin\n'
>>> repr('\tgherkin\n')
"'\\tgherkin\\n'"
>>> print('\tgherkin\n')
gherkin
>>> print(repr('\tgherkin\n'))
'\tgherkin\n'
Consider:
>>> r"what"ever"
SyntaxError: invalid syntax
>>> r"what\"ever"
'what\\"ever'
So how do we get the quote, but not the slash?
And please don't suggest r'what"ever', because then the question just becomes how do we include both types of quotes?
Related
If you want to use double quotes in strings but not single quotes, you can just use single quotes as the delimiter instead:
r'what"ever'
If you need both kinds of quotes in your string, use a triple-quoted string:
r"""what"ev'er"""
If you want to include both kinds of triple-quoted strings in your string (an extremely unlikely case), you can't do it, and you'll have to use non-raw strings with escapes.
If you need any type of quoting (single, double, and triple for both) you can "combine"(0) the strings:
>>> raw_string_with_quotes = r'double"' r"single'" r'''double triple""" ''' r"""single triple''' """
>>> print raw_string_with_quotes
double"single'double triple""" single triple'''
You may also "combine"(0) raw strings with non-raw strings:
>>> r'raw_string\n' 'non-raw string\n'
'raw_string\\nnon-raw string\n'
(0): In fact, the Python parser joins the strings, and it does not create multiple strings. If you add the "+" operator, then multiple strings are created and combined.
Python has more than one way to do strings. The following string syntax would allow you to use double quotes:
'''what"ever'''
Nevermind, the answer is raw triple-quoted strings:
r"""what"ever"""
Since I stumbled on this answer, and it greatly helped me, but I found a minor syntactic issue, I felt I should save others possible frustration. The triple quoted string works for this scenario as described, but note that if the " you want in the string occurs at the end of the string itself:
somestr = """This is a string with a special need to have a " in it at the end""""
You will hit an error at execution because the """" (4) quotes in a row confuses the string reader, as it thinks it has hit the end of the string already and then finds a random " out there. You can validate this by inserting a space into the 4 quotes like so: " """ and it will not have the error.
In this special case you will need to either use:
somestr = 'This.....at the end"'
or use the method described above of building multiple strings with mixed " and ' and then concatenating them after the fact.
Just to include new Python f String compatible functionality:
var_a = 10
f"""This is my quoted variable: "{var_a}". """
Use:
dqote='"'
sqote="'"
Use the '+' operator and dqote and squote variables to get what you need.
If I want sed -e s/",u'"/",'"/g -e s/^"u'"/"'"/, you can try the following:
dqote='"'
sqote="'"
cmd1="sed -e s/" + dqote + ",u'" + dqote + "/" + dqote + ",'" + dqote + '/g -e s/^"u' + sqote + dqote + '/' + dqote + sqote + dqote + '/'
I want to check whether the given string is single- or double-quoted. If it is single quote I want to convert it to be double quote, else it has to be same double quote.
There is no difference between "single quoted" and "double quoted" strings in Python:
both are parsed internally to string objects.
I mean:
a = "European Swallow"
b = 'African Swallow'
Are internally string objects.
However you might mean to add an extra quote inside an string object, so that the content itself show up quoted when printed/exported?
c = "'Unladen Swallow'"
If you have a mix of quotes inside a string like:
a = """ Merry "Christmas"! Happy 'new year'! """
Then you can use the "replace" method to convert then all into one type:
a = a.replace('"', "'")
If you happen to have nested strings, then replace first the existing quotes to escaped quotes, and later the otuer quotes:
a = """This is an example: "containing 'nested' strings" """
a = a.replace("'", "\\\'")
a = a.replace('"', "'")
Sounds like you are working with JSON. I would just make sure it is always a double quoted like this:
doubleQString = "{0}".format('my normal string')
with open('sampledict.json','w') as f:
json.dump(doubleQString ,f)
Notice I'm using dump, not dumps.
Sampledict.json will look like this:
"my normal string"
In my case I needed to print list in json format.
This worked for me:
f'''"inputs" : {str(vec).replace("'", '"')},\n'''
Output:
"inputs" : ["Input_Vector0_0_0", "Input_Vector0_0_1"],
Before without replace:
f'"inputs" : {vec},\n'
"inputs" : ['Input_Vector0_0_0', 'Input_Vector0_0_1'],
The difference is only on input. They are the same.
s = "hi"
t = 'hi'
s == t
True
You can even do:
"hi" == 'hi'
True
Providing both methods is useful because you can for example have your string contain either ' or " directly without escaping.
In Python, there is no difference between strings that are single or double quoted, so I don't know why you would want to do this. However, if you actually mean single quote characters inside a string, then to replace them with double quotes, you would do this: mystring.replace('\'', '"')
Actually, none of the answers above as far as I know answers the question, the question how to convert a single quoted string to a double quoted one, regardless if for python is interchangeable one can be using Python to autogenerate code where is not.
One example can be trying to generate a SQL statement where which quotes are used can be very important, and furthermore a simple replace between double quote and single quote may not be so simple (i.e., you may have double quotes enclosed in single quotes).
print('INSERT INTO xx.xx VALUES' + str(tuple(['a',"b'c",'dfg'])) +';')
Which returns:
INSERT INTO xx.xx VALUES('a', "b'c", 'dfg');
At the moment I do not have a clear answer for this particular question but I thought worth pointing out in case someone knows. (Will come back if I figure it out though)
If you're talking about converting quotes inside a string, One thing you could do is replace single quotes with double quotes in the resulting string and use that. Something like this:
def toDouble(stmt):
return stmt.replace("'",'"')