Adding string to set python

How to add multiple strings to a set in Python?

Use the and Functions to Convert a Set to a String in Python In this approach, we will convert each element of a set into a string and then join them to get a single string where we will use as a delimiter. This tutorial will discuss how to convert a set to string and view it as the latter in Python.

Convert Set to String in Python

This tutorial demonstrates how to convert a Python set to a string using optimum techniques.

We can employ two techniques for the required conversion.

Let us start by taking a sample set to work on.

Now we have a set that we will convert into a string.

Use the map() and join() Functions to Convert a Set to a String in Python

In this approach, we will convert each element of a set into a string and then join them to get a single string where we will use ‘,’ as a delimiter. We do this in the following way.

str_new = ', '.join(list(map(str, se))) 

In the above code, the map() function takes each set element and converts them into a string stored in a list using the list() function. The join() function then joins the individual string elements in the string with ‘,’ as a delimiter and returns a single string.

We will now print the new string along with the data type.

print(str_new) print(type(str_new)) 

The above code gives us the below output.

The output shows that we have converted our set into a string.

Use the repr() Function to Convert a Set to a String in Python

This approach will convert our set into a string using the repr() function. We will use the same sample set as in the above technique.

We will create a new variable to store the return value of the repr() function.

As we can see above, we need to pass our input set to the repr() function, and it returns the string. We will print the new variable and its data type to ensure our conversion was successful.

print(r_str) print(type(r_str)) 

The above results into below output.

Our set was successfully converted to a string, as we can see above.

Thus we have successfully learned multiple techniques to convert Python set into a string.

Python String

String — Python Replace \\ with \, In Python string literals, backslash is an escape character. This is also true when the interactive prompt shows you the value of a string. It will give you …

How to add multiple strings to a set in Python?

I am new to Python. When I added a string with add() function, it worked well. But when I tried to add multiple strings, it treated them as character items.

>>> set1 = >>> set1.add('de') >>> set1 set(['a', 'de', 'bc']) >>> set1.update('fg', 'hi') >>> set1 set(['a', 'g', 'f', 'i', 'h', 'de', 'bc']) >>> 

The results I wanted are set([‘a’, ‘de’, ‘bc’, ‘fg’, ‘hi’])

Does this mean the update() function does not work for adding strings?

The version of Python used is: Python 2.7.1

update treats its arguments as sets. Thus supplied string ‘fg’ is implicitly converted to a set of ‘f’ and ‘g’.

You gave update() multiple iterables (strings are iterable) so it iterated over each of those, adding the items (characters) of each. Give it one iterable (such as a list) containing the strings you wish to add.

Here’s something fun using pipe equals ( |= ).

>>> set1 = >>> set1.add('de') >>> set1 set(['a', 'de', 'bc']) >>> set1 |= set(['fg', 'hi']) >>> set1 set(['a', 'hi', 'de', 'fg', 'bc']) 

Try using set1.update( [‘fg’, ‘hi’] ) or set1.update( )

Each item in the passed in list or set of strings will be added to the set

Convert regular Python string to raw string, 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 Replace \\ with \

So I can’t seem to figure this out. I have a string say, «a\\nb» and I want this to become «a\nb» . I’ve tried all the following and none seem to work;

>>> a 'a\\nb' >>> a.replace("\\","\") File "", line 1 a.replace("\\","\") ^ SyntaxError: EOL while scanning string literal >>> a.replace("\\",r"\") File "", line 1 a.replace("\\",r"\") ^ SyntaxError: EOL while scanning string literal >>> a.replace("\\",r"\\") 'a\\\\nb' >>> a.replace("\\","\\") 'a\\nb' 

I really don’t understand why the last one works, because this works fine:

Is there something I’m missing here?

EDIT I understand that \ is an escape character. What I’m trying to do here is turn all \\n \\t etc. into \n \t etc. and replace doesn’t seem to be working the way I imagined it would.

>>> a = "a\\nb" >>> b = "a\nb" >>> print a a\nb >>> print b a b >>> a.replace("\\","\\") 'a\\nb' >>> a.replace("\\\\","\\") 'a\\nb' 

I want string a to look like string b. But replace isn’t replacing slashes like I thought it would.

There’s no need to use replace for this.

What you have is a encoded string (using the string_escape encoding) and you want to decode it:

>>> s = r"Escaped\nNewline" >>> print s Escaped\nNewline >>> s.decode('string_escape') 'Escaped\nNewline' >>> print s.decode('string_escape') Escaped Newline >>> "a\\nb".decode('string_escape') 'a\nb' 

>>> import codecs >>> codecs.decode('\\n\\x21', 'unicode_escape') '\n!' 

You are missing, that \ is the escape character.

Look here: http://docs.python.org/reference/lexical_analysis.html at 2.4.1 «Escape Sequence»

Most importantly \n is a newline character. And \\ is an escaped escape character 😀

>>> a = 'a\\\\nb' >>> a 'a\\\\nb' >>> print a a\\nb >>> a.replace('\\\\', '\\') 'a\\nb' >>> print a.replace('\\\\', '\\') a\nb 

Your original string, a = ‘a\\nb’ does not actually have two ‘\’ characters, the first one is an escape for the latter. If you do, print a , you’ll see that you actually have only one ‘\’ character.

If, however, what you mean is to interpret the ‘\n’ as a newline character, without escaping the slash, then:

>>> b = a.replace('\\n', '\n') >>> b 'a\nb' >>> print b a b 

Convert Set to String in Python, Use the repr () Function to Convert a Set to a String in Python This approach will convert our set into a string using the repr () function. We will use …

Convert set to String in Python

Sets are an unordered collection of elements in Python. It does not contain duplicate elements and can be defined using the set() function in Python.

Ways to Convert set to string in Python

This tutorial will discuss how to convert a set to string and view it as the latter in Python. We can verify the result using the type() function.

Using the str() function

In Python, we use the str() function to typecast objects and convert them to strings. Internally, it invokes the __str__() function.

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Convert String to Set Python

Converting a string to a set in Python assists in easier manipulation of the text, as it removes duplicate characters and orders the characters in the string alphabetically. Python provides various ways to convert the input string to a set. In this post, we will overview each of these methods using the appropriate examples.

This article will cover the following approaches to convert the specified strings to set in Python:

Method 1: Convert String to Set in Python Using the “set()” Function

The “set()” function creates the Python set object which has unique and unordered elements. The method can be used here to perform the discussed conversion.

Here, “iterable” is an optional parameter that specifies the “sequence”, “collection”, or “iterator object” that needs to be converted into a set. If an iterable is not given, an empty set is created.

Let’s overview the following example code:

string_value = «Python Guide»
print ( string_value )
print ( str ( type ( string_value ) ) , ‘\n’ )
set_value = set ( string_value )
print ( set_value )
print ( str ( type ( set_value ) ) )

In the above code, the “string” value is initialized and converted into the set using the “set()” function. The “type()” function is applied twice before and after the conversion(to set) to check the data type.

The “string” in the above snippet has been converted into a “set“.

Method 2: Convert String to Set in Python Using the “add()” Method

In Python, the “add()” method is utilized to add an element/item to a set. The “add()” method takes a single argument which is the element/items to be added to the set. It does not return any value. This method can be applied to append the initialized string into an empty set.

In the above syntax, “set” is the name of the set object, and “element” corresponds to the item that needs to be added.

The below example code is used to convert string to set in Python:

string_value = «Python»
set_value = set ( )
for character in string_value:
set_value.add ( character )
print ( set_value )
print ( type ( set_value ) )

In the above lines of code, the string, and empty set are initialized, respectively. After that, the “for” loop is applied along with the “add()” function to iterate over the string and append the string characters into the empty set.

The above output shows that the string has been iterated and appended into the set accordingly.

Method 3: Convert String to Set in Python Using “Set Comprehension”

In Python, “set comprehension” is utilized to generate a set from a current iterable, such as a list or a string. This approach is utilized to convert the given string into the set via a “for” loop.

• “expression” is any valid Python expression that can be applied to the element.
• “iterable” is any iterable object like a set, tuple, list, etc.
• “condition” is an optional filter that selects which elements to include in the new set.

Let’s overview the following code:

string_value = «Python»
set_value = { i for i in string_value }
print ( set_value )
print ( type ( set_value ) )

In the above code block, “set comprehension” is used along with the “for” loop to create a set with each string character as individual elements.

Based on the above output, it can be verified that the input string has been converted into a set. It is such that the string characters are appended into a set.

Conclusion

To convert the given string to a set, the “set()” function, “add()” method, or “set comprehension” can be used in Python. The inbuilt “set()” function is used along with the “str()” function to transform/convert the given string to a set in Python. The “add()” and “set comprehension” approaches perform the conversion via iterating through the string value. This Python post presented various ways to convert the string to a set.

About the author

Talha Saif Malik

Talha is a contributor at Linux Hint with a vision to bring value and do useful things for the world. He loves to read, write and speak about Linux, Data, Computers and Technology.

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