Just running that code above created another variable "k" that changed the position of "x" in the dict. We will convert a string into a variable name with multiple ways like exec() function, locals() function and globals() function. By giving the format() method the variable as an input, we may utilise this technique to turn a variable into a string. Ask Question Asked 13 years, 9 months ago Modified 2 months ago Viewed 169k times 113 I would like to convert a python variable name into the string equivalent as shown. rev2023.7.7.43526. IE: you can ship a bug, you thought you were testing. simply because of a bad method name refactor. You need to duplicate the globals dictionary since its size will change as soon as you define a new variable. I will try to help you as soon as possible. A String representation of the value stored inside the number is created using the f-string method. People always blindly freak out about exec/eval that they never understand how powerful and useful it can be when used correctly. [duplicate], Why on earth are people paying for digital real estate? The print() function is used to output the value of the string variable to the console. I don't know in advance what is the type of a. I just take numpy.ndarray as an example. 5. Last modified: Feb 15, 2023 By Alexander Williams. Why free-market capitalism has became more associated to the right than to the left, to which it originally belonged? Use our color picker to find different RGB, HEX and HSL colors, W3Schools Coding Game! At last, we have printed the input string and see if the string contains a variable name or not. The format() method is called on the string, which replaces the placeholders with the values of name and age. Data manipulation: In some cases, you might need to combine data with other strings to manipulate it. The placeholders are defined using curly braces, with the first one representing the name and the second one representing the age. The tostring() is a method to convert other data types into strings. Technically the information is available to you, but as others have asked, how would you make use of it in a sensible way? The most obvious alternative to what you request is a dictionary. If you create a variable, you can easily convert it to a string using the print function. Please read Why is using 'eval' a bad practice? What does the "yield" keyword do in Python? calling "%s" directly in print() and storing the value in a variable. Note that similar to lists' and arrays' indexing, here also the indexing begins with 0. How do I create a directory, and any missing parent directories? Just make sure you put them into the dictionary first. For example, It evaluates an expression stored in a string as if it were Python code. text = subprocess.check_output(["ls", "-l"], text=True) For Python 3.6, Popen accepts an encoding keyword: Three different names have that object bound to them, and all are equally valid. In this case, the above code will print multiple names. Other than Will Riker and Deanna Troi, have we seen on-screen any commanding officers on starships who are married? Restructure your code. Asking for help, clarification, or responding to other answers. Not the answer you're looking for? Python currently has no method to do this. & Its Benefits & Types, Python vs R: Know these 5 Key Differences. I.e. For example, To check if a variable is of a certain type you can use isinstance, so to convert the type of b depending on the type of a you can do something like. Create your own server using Python, PHP, React.js, Node.js, Java, C#, etc. Because argument_data identifier name is not available in the random_function()'s namespace, this would yield instead: Now, consider the hypotetical usage of a get_indentifier_name_missing_function() which would behave as described above. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, @Mr.goosberry, I want to do this in a python script. Using str (): Str () is a Python built-in function that can be used to convert a variable to string. There are many problems that require typecasting of data (objects) into strings. In my case, I would like to create a decorator, that adds a new variable to a class by the varialbename i pass it: But if your method returns ambigous results, how can I know the name of the variable I added? Notice how the type() returns for "1" while for 4. In this tutorial, we're going to learn 4 methods to insert a variable into a string. With the "%" operator, we can insert a variable into a string.%s: for string.%d: for integer. W3Schools offers a wide range of services and products for beginners and professionals, helping millions of people everyday to learn and master new skills. Asking for help, clarification, or responding to other answers. It is considered the best method for converting a variable to a string in Python due to several reasons: 1. how to convert variables to strings in python, which is a common activity. Using Lin Reg parameters without Original Dataset. A string is a sequence of one or more characters (letters, numbers, symbols). In this tutorial, we will be focusing on this topic only to convert a Python string to a variable name. Creates a list of integers called numbers. Does Python have a string 'contains' substring method? For example. We have discussed all the ways through which we can convert a string into a variable name. These characters include everything: lowercase alphabets a-z, capital alphabets A-Z, numbers 0-9, all special characters like #, $, &, and blank spaces. Relativistic time dilation and the biological process of aging. But maybe this is a useful start for you. There are a number of functions, like patch.object, that take the name of a method or property to be patched or accessed. We got to know about many topics in python. This shows that the variable name is present as a string in the globals() dictionary. Example. How do I merge two dictionaries in a single expression in Python? As seen above, the major concern while dealing with strings is while printing them. Totally possible with the python-varname package (python3): I searched for this question because I wanted a Python program to print assignment statements for some of the variables in the program. 1. Here, we will use the first placeholder for the string name, and the second placeholder for the value of the variable that we will create from the string variable. In fact, in the python script, it receive some strings from sys.argv. The above example displayed the basic use of f-strings. Convert String Into Variable Name in Python Using the locals() Method, Convert String Into Variable Name in Python Using the globals() Method, String Into Variable Name in Python Using the vars() Function, Convert String Into Variable Name in Python Using the exec() Function, Convert String Into Variable Name in Python Using the setattr() Function, Python Dictionary How To Create Dictionaries In Python, Python String Concatenation and Formatting, Python Continue vs Break Statement Explained, Python Pass Keyword Explained With Examples. The list that is created contains one or more names (as strings) that are bound to the value of the variable passed to variablename(). Note that in python the variables to not have a fixed "type", so you can simply reassign a variable to convert its type. Im using the globals() option, which is working but its still printing out my initial string rather than the new set variable. To convert a string to a list of its individual letters in Python, you can use the built-in list() function. You can use a Dictionary to keep track of the keys and values. For a user defined class to be converted to string representation, __str__() function needs to be defined in it. How to do this? (Otherwise you could just assign b to an empty object of the new type and be done with it.). %s: for string. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. It then creates another variable called age and sets it to the integer value 25. The real challenge here is that you are not guaranteed to get back the variable name by itself. It is approved and widely used, therefore many Python modules and frameworks are compatible with it. If so, the tuple passes the test and is returned by ifilter(). Using the built-in str() function is the main approach weve covered. It is a built-in function that is considerably more performant than other conversion techniques in general. Python | Check if string ends with any string in given list, Pandas AI: The Generative AI Python Library, Python for Kids - Fun Tutorial to Learn Python Programming, A-143, 9th Floor, Sovereign Corporate Tower, Sector-136, Noida, Uttar Pradesh - 201305, We use cookies to ensure you have the best browsing experience on our website. Strings can be formatted by substituting placeholders with variable values using the % operator. If string is palindrome then execute if block otherwise execute else block. Pick up [0] element of the list if you need variable name only. 2. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Hence the f-strings came into existence. By using our site, you To conduct string concatenation and other string manipulation operations in these circumstances, you must transform the variable to a string. The str() function 'converts'the object into a String and 'returns' the value. I'd like to point out a use case for this that is not an anti-pattern, and there is no better way to do it. Not the answer you're looking for? How much space did the 68000 registers take up? This would: assert that the var is bound to the obj and return the name of the member. It would only see the a_dictionary_object identifier name. In the movie Looper, why do assassins in the future use inaccurate weapons such as blunderbuss? Not the answer you're looking for? To convert a list into a python array, use numpy.asarray. Problem: Write a program that takes a tuple of integers as input and converts each integer to its binary representation as a string. First, you might want to consider the following: This function grabs the global variables and filters out the ones matching the content of your variable. Now, suppose you have the integer object with value 1, and you want to work backwards and find its name. For this, I made some small changes to your tostr() function. But for now it can work by iterating an object or the caller's frame: patch.member(obj, obj.method_name, new_reg). Output: Python requires variables to be in string format when printing them. There might be some clever way to hack the Python bytecodes or something to get the value of the name, but that is at best a parlor trick. Python consists of multiple methods for solving problems i.e. Initializes an empty string called concatenated_string. If you tell us what you want this capability for, more helpful information could possibly be given. All methods work perfectly.Happy codding. It takes an object as input and returns a string. How to Convert a String to Variable Name in Python? The proper answer should be print(Buffalo) should be 4 such as print(x), rather than print(my_dict["Buffalo"]). Can Visa, Mastercard credit/debit cards be used to receive online payments? 1 2 a = 5 print(a) The variable is an integer, that is converted to a string with the print function. although when i print out the actual variable (by calling the name of it that the string is) it prints out the value i set it to. feed the eval() function in order to get a reference to the actual identifier, and therefore, a reference to the real data: Unfortunately, this doesn't work in all cases. Note that it's possible to have the same value bound to multiple names. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. The join() method is then used on an empty string with the list as its argument to concatenate the elements of the list into a single string. I take ownership of my work and believe in constant of scaling interested in learning new technology and ready to take up new challenges. How to convert string to integer in Python? There are multiple ways to convert a string to a variable name. the current scope. python string I want to check the name of a variable in a loop! What would stop a large spaceship from looking like a flying brick? I don't get it this solution. Convert Variable Name to String? Read "Python 2 vs Python 3: Practical Considerations" for more information about the differences between Python 2 and Python 3. You can look up the word and get the definition. These methods have their own advantages and applications. Maybe if I will also check the local list I could at least remove the "dependency"-Variable from the list, but this will not be a reliable result. A string variable is created with placeholders for name and age. Chris, your comment doesn't seem to relate to my answer or the original question. A list is created using the square brackets and the string value of num is the only element in the list. Two variables are created: name with a string value of John and age with an integer value of 25. In fact, in the python script, it receive some strings from, If your question was about converting specifically from, Thanks, John. Thanks for contributing an answer to Stack Overflow! For example, it might print "foo = 3, bar = 21, baz = 432". Thanks for contributing an answer to Stack Overflow! delimiter is not working. Python offers a format method, that takes in variables and inputs them into strings. Let's take an example: However, the default __str__() method does not transform the object to a string and instead displays object information in a human-readable format. What would a privileged/preferred reference frame look like if it existed? Connect and share knowledge within a single location that is structured and easy to search. rev2023.7.7.43526. It can work with any other word and definition. How does the theory of evolution make it less likely that the world is designed? To get it called properly, I put it inside a list comprehension [tpl[0] for tpl globals().items())]. acknowledge that you have read and understood our. There are a number of languages that provide that functionality - even C/C++ compiled to machine-language can via defines; Python boasts as easy to use entry point for programming but lacks such a popular tool for people to learn and see what their program is doing; Like C/C++, a "compile-time" function could do the job perfectly but it seems all suggested methods of trying to locate a variable name in globals() or etc is only partially successful and cannot work 100% of the time. Convert String Into Variable Name in Python Using the globals() Method String Into Variable Name in Python Using the vars() Function @BillalBEGUERADJ Thank you for adding some sense to the conversation. The basic syntax of the format method is: Let's take an example to display the use of the format method: I've used the format method while calling variables(all objects). The community reviewed whether to reopen this question 4 months ago and left it closed: Original close reason(s) were not resolved. Unfortunately, get_indentifier_name_missing_function() would not see the 'original' identifier names (some_dictionary_,some_other_dictionary_2,some_other_dictionary_n). But, have you ever use the input string as the variable name in your program. delimiter is not working. Iterating over dictionaries using 'for' loops. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. In this example, we will be taking the input as a string. Next, the code creates a string variable called string with two placeholders using %s for the name and %d for the age. While using W3Schools, you agree to have read and accepted our, Any object. Ask the user for an integer value and convert it into int and store value inside variable name number. Using exec() Method in Python to Convert a Python string to a Variable Name, 2. I've also used the '+' operator with an integer type variable to depict the error. Is there any potential negative effect of adding something to the PATH variable that is not yet installed on the system? Let us look in detail with the help of the example explained below: The locals() function in python is used to return the dictionary of the current local symbol table. Then, we have modified the value of the given string through the locals dictionary through the locals() function. As "is" operator behaves unexpectedly with integers shows, low integers and strings of the same value get cached by python so that your variablename-function might priovide ambigous results with a high probability. It isnt easy to keep all the tracks of lexical references: if we create arbitrary variable names, conflicts can occur. 3. The str() function and print()function internally calls for __str__() method to do the task. Unfortunately, this doesn't seem to work in python 3 anymore. I would like to convert a python variable name into the string equivalent as shown. Understanding the various techniques to convert a variable to a string can help you work efficiently with data manipulation, output, and other tasks in Python. How to Convert an Integer to String in Python? Not sure if this could be used in production code, but in Python 3.8(and up) you can use f' string debugging specifier. Please enter your email address. Find centralized, trusted content and collaborate around the technologies you use most. Connect and share knowledge within a single location that is structured and easy to search. Split it with .split('=') and get a List of 2 strings, [0] - your_variable_name, and [1] - actual object of variable. I wanted to retrieve from globals() the key corresponding to the value of each variable. Sounds like an XY problem. I checked this question because, using RPy2, I want to pass a Python variable with an eponymous R name. It is bad to be in a situation where eval looks like the best option. String formatting: Python offers a variety of methods for formatting strings, including f-strings, the format() method, and the % operator. I'm looking for something similar to the r'' method. Find centralized, trusted content and collaborate around the technologies you use most. # storing converted value into another variable, # Using format method to create a string of multiple variables, # Using format method on integer variable, # Note that variable is not typecasted into String, "This is a {1} {2} read article and it takes {0} {2} to try the code. We also covered the use of f-strings, the format() method, the % operator, and the join() technique. The '{}' brackets represent the space for variable values to be printed. How to Change Column Type in PySpark Dataframe ? Is there a legal way for a country to gain territory from another through a referendum? Would a room-sized coil used for inductive coupling and wireless energy transfer be feasible? We and our partners share information on your use of this website to help improve your experience. 4. Also, you can also index the variables in order to use them again without repeating the code. The str() method can also be used on Lists to convert an object into a string. http://docs.djangoproject.com/en/dev//topics/db/models/#verbose-field-names. Strings representing the name of an identifier, can only be referenced back to the actual identifier by the. However, depending on the task at hand, a number of additional techniques are available that can be used for certain objectives. Also, this type of conversion will likely throw exception if b cannot be converted into the type of a, so a try-catch construct will probably be beneficial. the TLDR states that it's not possible to achieve what has been asked by the OP. python string Share Follow edited Jul 31, 2022 at 4:45 Karl Knechtel 61.9k 11 98 149 asked Dec 11, 2010 at 4:49 rectangletangle 50.1k 93 204 275 10 Raw strings are just a different syntax when defining a string constant. value into a string. Sorry for unclear description. Also, here is an even better example: In practice, Python reuses the same object for integers with common values like 0 or 1, so the first example should bind the same object to all three names. Finally, the resulting string is printed to the console using the print() function. Since these return a string, they can either be stored in a variable or directly printed using the print() function. Thus, we can simply do: globals () ['p'+ (str (y)+str (x))] Which evaluates to globals () ['p01'], which gets the value of global p01 - which is bye. Why does this happen? How do countries vote when appointing a judge to the European Court of Justice? Some cases may arise when there is a need to convert a variable to a string when working with data output and modification. Specifies the object to convert into a string, The encoding of the object. cat = 5 dog = 3 fish = 7 animals= [cat, dog, fish] for animal in animals: # by animal name, I mean the variable name that's being used print (animal_name + str (animal)) It should print out cat5 dog3 fish7 So I am wondering if there is an actual method or function I could use to retrieve the variable name being used as a string. You could provide the user with the exact variable name in question while keeping your code generic e.g. Can Visa, Mastercard credit/debit cards be used to receive online payments? I want to reassign the type of one variable according to that of another variable. Applying the format method hasn't made any change in the original variable. Strings are amongst the most popular types in Python. rev2023.7.7.43526. In other words, we will be creating dynamic variable names and assigning a value to them. In this example, we will have a variable named by us and an input string. Non-definability of graph 3-colorability in first-order logic, Typo in cover letter of the journal name where my manuscript is currently under review. It seems like you're asking how to solve a problem the wrong way. 15amp 120v adaptor plug for old 6-20 250v receptacle? The format method is generally used to ease outdisplaying multiplevalues/variables (objects other than String). why isn't the aleph fixed point the largest cardinal number? Also, here are some methods to convert int to string in python. Remember that the variable names in format() should follow the sequence of '{}' brackets. Making statements based on opinion; back them up with references or personal experience. Does my_dict["Buffalo"] prints 4? Python doesn't have a method named tostring(), but it offers other methods which do the task for you. At last, we will print the input string and convert a string into a variable name. I want to do this in a python script. Making statements based on opinion; back them up with references or personal experience. Thank you @synthase ! Output: Note the TypeErroroccurred due to the use of 'int' instead of 'str'. By using split () method. The formatted string is printed using the print() function. Once executed, the format() method will return a string that looks like a Python statement with myStr as the variable name to which the given value is assigned. For this, I made some small changes to your tostr() function: ` def variabletostr(**df): variablename = list(df.keys())[0] return variablename variabletostr(df=0) ` FYI: I added this code as a new post in this thread. There's a lot of confusion between the repr() method and the str() method. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. Simplicity: It offers a simple and straightforward way to convert a variable into a string. Enjoy our free tutorials like millions of other internet users since 1999, Explore our selection of references covering all popular coding languages, Create your own website with W3Schools Spaces - no setup required, Test your skills with different exercises, Test yourself with multiple choice questions, Create a free W3Schools Account to Improve Your Learning Experience, Track your learning progress at W3Schools and collect rewards, Become a PRO user and unlock powerful features (ad-free, hosting, videos,..), Not sure where you want to start? In your case, 'p'+(str(y)+str(x)) becomes 'p01', so it gets the result of the expression p01, which is of course 'bye'. f-strings are another form of the format method. There is something not right in Python if to obtain the name of an object we need a 5 pages answer on StackOverflow. How to disable (or remap) the Office Hot-key. Rethink and restructure. But if MyDict[sys.argv[1]] is a numpy.ndarray, the literal_eval cann't reassign the list [[[100, 200, 300]]] into a numpy.ndarray. Using f-strings you can directly use the variable within the string by enclosing them between '{}'. Changing, objects don't have names, names have objects. Is there a distinction between the diminutive suffices -l and -chen? If your variable type is an integer, you must convert it to a string before concatenation.To convert, we'll use the str() function. Do United same day changes apply for travel starting on different airlines? Also, there's a similar question, but about Ruby. What if. It is simple to use and comprehend as a result. Convert string "Jun 1 2005 1:33PM" into datetime. Thus, we can simply do: Which evaluates to globals()['p01'], which gets the value of global p01 - which is bye. Shop replaced my chain, bike had less than 400 miles. Variable placeholders can be added to a prepared string using the format() method. Output: This code also works the same way as that of globals().The only difference is that we have used the function locals() here.. To convert objects into strings, f-strings can be used as-, Check out how the types of articles and num differ due to f-strings -. In this example, the decode method is used to convert the byte string back to a Unicode string encoded in UTF-8 format. Very generally, you would call the new type's constructor, passing in the old value. Let's begin with the list below: The str() functionin Python is considereda substitute for tostring() method offered by other programming languages. Currently one needs to pass to a function: the string representing the identifier name, You are searching for a variable by its value, objects are a core concept in Python, and they may be assigned a variable, but the variable itself is a bound name (think pointer or reference) not the object itself, different name references to the same object will all share the same. . "There is absolutely no reason to ever do what you describe" - We have a local all-knowing entity here. How to convert categorical string data into numeric in Python? This makes it a class method for returning strings. These predefined variables may be int, list, numpy.ndarray, or else. Can I contact the editor with relevant personal information in hope to speed-up the review process? So in this case, you have the word "Buffalo" and it's definition is 4. After obtaining the string containing the Python statement, we will pass it to the. You don't know if he's writing production code or just experimenting with language features for his own education. What is the Modified Apollo option for a potential LEO transport? A dictionary is very similar to a real life dictionary. Converting with Strings. The program should then concatenate the strings to form a single string and print it. Function parameters: Several Python functions have a set format for the parameters, which may be a string. 587), The Overflow #185: The hardest part of software is requirements, Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned, Testing native, sponsored banner ads on Stack Overflow (starting July 6).
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