Dynamically create variable names python

Dynamically create variable names python. Look into python's glob module. length; ++i) {. A Python variable is a name given to a memory location. You can't do it if you keep data in your variables names (instead of datastructures like list, dict etc). One of the powerful features of the exec() function is its ability to create variables dynamically. Don't use it here. I need something like to create 4 list objects like depth_1,depth_2,depth_3,depth Oct 5, 2016 · I have written some classes I would like to test by creating multiple instances of my classes. 160k 44 217 306. If you don't want to use an explicit mapping system, then you can use one of Python's built-in mapping systems, though it's much less nice and explicit in my opinion. Firebug gives me this: missing ; before statement. So, now the required output is something like tom_out_df which should be same as out_df. a = {} for x in range(1,21): a[x] = x**2 b = [] for x in range(1,21): b. plot(x,y) # Or whatever you want in the subplot. Let user_name = 'tom'. Jan 10, 2012 · Is it possible to create a local variables with Python code, given only the variable's name (a string), so that subsequent calls to "'xxx' in locals()" will return True? Dec 5, 2016 · 2. Sep 5, 2022 · I have a variable like YEAR = 2022 Now I want to make a automate variable like Sales_Report_'YEAR's value(2022). apache-spark. Last Updated : 13 Sep, 2022. In response to your update: The only way to do this is with a mapping system. price1 = 5. But in those rare cases where you need to create variable names on the fly, you can use attr() for object attributes, and either locals() or globals() for accessing variables through a dictionary interface. the Tin Man. Enter table name: I should enter the table name. Assign a variable that holds the new dataframe name. If there is another way for me to create class instances and then access them later with the "s" variable that would work too. execute(query) One thing to be mindful of is the source of the value for the table name. txt while the latter would. The key will act as the variable name and the value as the variable value. ## get the reference to the current module - key trick to get the ref to same module. Mar 24, 2021 · Dynamically assigning variables using a For Loop can be done with the help of a Dictionary. Dec 23, 2013 · For some reasons see Why you don't want to create dynamic variables and Never use dynamic variable names. close() what I wanted was that the compiler should as. Python 3 change the names dynamically. Using exec built-in function : This function is used for the dynamic execution of Python program which can either be a string or object code Jul 3, 2017 · My minimal working example is the following: I have a loop iterating a certain number of times. Using the exec command. if you have an array of base classes and you want to create a class using it (which you can't do with Python's class syntax). and I guess there is something wrong with marker+i. I want to store the key value dynamically. Apr 21, 2021 · To create a dynamic variable name in Python use a dictionary. Formatted string literals enable us to include expressions and variables inside of a string by prefixing the string with f. Mar 12, 2020 · Dynamic Variable Names Python [duplicate] Ask Question Asked 4 years, 1 month ago. Is it possible to make a string become a variable?-2. It uses the usual shell wildcard syntax, so ?? would match any two characters, while * would match anything. That way madness lies. 1. health . For example, the following code creates a dynamic variable named y and assigns it the value 20: python y = locals()["x"] * 2 print(y) Output: 20 * **Using a for loop:** You can also use a for loop to create dynamic variable names. – 95. # Changing Case of Variable Names. getGroup(selected, header+i) If you insist on actually modifying local variables, you could use the locals function: locals()["group"+str(i)] = self. Dec 16, 2011 · In general it is both cleaner and more extensible to use an ADT (a list in this case) to represent the given problem than trying to create "dynamic variables" or "variable variables". You could use either f??. Dictionaries are mutable, which means we can edit the name and the content of the variable at any time. You should at least rename the variables above so one can see which one belongs to which player. Jan 26, 2022 · I would like to assign variable (matrices names) dynamically and assigning some values. At each iteration, I would like to create a new key with a name depending on the current index value, Dec 24, 2019 · How do you create different variable names while in a loop? [duplicate] (9 answers) May 20, 2010 · The difference is that in PHP, you represent the name of the class you want to refer to as a string, while in Python you can reference the same class directly. txt or f*. It is the basic unit of storage in a program. And I'd want for myMsg and anotherMessages to be passed from a list (for example, the hard part that I am clueless and I need help with is how to take strings into variables to be inputs of a function). 5. Python3. format() # Create a file name using Variables in Python. Enter table name: inventory. If you can get away with just having one dict to manage all your variable names instead of say 100 names in your global scope, it makes life much easier. Feb 9, 2019 · I want to create a "Client" class, and generate objects in that class in a loop. This can be particularly useful when you need to generate variable names based on certain patterns or data. txt'. this = sys. To some degree, this is true anytime you create a dictionary or a list. Each object would have a username and a password, and would be stored in a variable that contains the client's ID. The first element of each of the sublists is the key and the second element is the value. You can even send this value as a parameter or loop it dynamically. use_potion(healthpotion) Here, my health potion is supposed to add 50 to the variable player. The Exec () methods helps us to execute the Python program dynamically. x. prices = [5, 12, 45] I want. Is there a way I can generate variable names in python in a loop and assign values to them? For example, if I have. I am looping over and hope to assign name of dataframe dynamicall inside loop, like. original_names = ["varOne", "VarTwo", "VarThree"] lowercase_names = [] for name in original_names: lowercase_name = name. The expected output is mat1 and mat2 containing values 1 and 1 respecti I have some logic which I need to repeat 6 times. For python 3, this use range not xrange; f. Jul 15, 2017 · I need to create a set to 4 another dataframe. Dynamic Variable Creation. You need to add the table name to the query string yourself. read_json(path_or_buf=filename, lines=True) The problem is I want each review category to have its own variable, like a dataframe called "beauty_reviews", and another called "pet_reviews Can you have a counter outside the function which counts how many times the function is called? If yes, pass that counter inside the function and use a dict to generate variable names as keys. Set the key as the name of the variable and the value as the content of the variable. tsp_data_unique['Clusters']. I am familiar with dynamically naming variables in the con Dec 24, 2012 · In python how can we create a new object without having a predefined Class and later dynamically add properties to it ? Mar 9, 2020 · Classes can be dynamically created using the type() function in Python. You assign a value for each name in the keyword arguments of the str. getattr(sys. Here is an example: dict= {} # create an empty dictionary. Apr 15, 2023 · Ignore the weird stuff at the start, and notice that we have the variable names from a to z, along with number and letter. Jun 21, 2021 · In my project, I want to be able to create a list of Querysets, where each Queryset is named after the category of their respective items. It is a structure that contains named rows and columns, on which arithmetic operations can be aligned. Oct 2, 2014 · The init method above creates two lists and I want to refer to them both dynamically: Jan 11, 2016 · I am a beginner in python and met with a requirement to declare/create some lists dynamically for in python script. where(y_km == i) You can then access the values in the dictionary using eg clusters['cluster_1']. format(num=i) for i in range(3)] print list_all # ['list_0', 'list_1', 'list_2'] So I guess the question is how can I dynamically create and execute python variable names? Apr 13, 2021 · To create a dynamic variable in Python, use a dictionary. Below are the methods to create dynamically named variables from user input. Apr 3, 2015 · Dynamicly define the function name and function body with variables in python. While using a list or dictionary is of course the right approach here, it is possible to create named variables, using exec (). We do not need to declare variables before using them or declare their type. list= [['a', 1], ['b', 2], ['a', 3], ['c', 4]] #list is our input where 'a','b','c', are keys and 1,2,3,4 are values. health,50) inventory. A dictionary in Python contains key/value pairs that can be of various data types. python: dynamically create and execute existing variable names. for i in range(len(list)): Feb 8, 2019 · In order to do so, I need to define a dynamic name to a dictionary. how do I create a dynamic string variable/name of dataframe. obj = globals()[parser['name']]() will access the global object of with name parser['name'] == 'foo Dec 19, 2018 · Furthermore, the variables in a module are actually just stored in a dictionary within the module (this is a simplification but good enough for now) so you're actually just coming up with a more complicated strategy for using a dictionary that you didn't declare. lower() 1) Version with lists being a list of lists (the numbers are just the order of the lists): 2) Same but with a for loop instead of a list comprehension: lists. The string may name an existing attribute or a new attribute. python dynamically set non-instance class attributes. It is unclear, which variable is assigned to which player. Jan 10, 2012 · Is it possible to create a local variables with Python code, given only the variable's name (a string), so that subsequent calls to "'xxx' in locals()" will return True? Jan 18, 2016 · It is generally better practice to just use a dict() and, then make your 'dynamic variable names' keys to the dictionary instead. Nov 29, 2011 · setattr(object, name, value) This is the counterpart of getattr(). For example, setattr(x, 'name', value) is equivalent to x. Unlike static variable names, where the variable name is explicitly defined, dynamic variable names allow developers to generate variable names based on certain conditions or patterns. end. format(table) c. it should get concatenated in the query: Oct 11, 2021 · Now I want to concat the dataframe name (out_df) with a variable user_name which is an input. filename = "D:\\Library\\reviews_{}. My main dataframe is df_PROD and every year, if the records are more than 1, I want to chunk them as separate dataframe. The function assigns the value to the attribute, provided the object allows it. how to create variable names dynamically and assigning values in python? 3. Conclusion Jun 14, 2018 · print eachRow. In most cases, people really want to be using a dict or a list. python. Create dataframe dynamically using exec method to copy data from source dataframe to the new dataframe dynamically and in the next line assign a value to new column. While the above uses indices, the more general form of "variable variables" is generally done with a dictionary: Create a file name using Variables using str. Feb 5, 2018 · I want that variable name be England_M instead of variable_name. May 30, 2018 · Right now I am learning Python and struggling with a few concepts of OOP, one of that being how difficult it is (to me) to dynamically initialize class instances and assign them to a dynamically generated variable name and why I am reading that I shouldn't do that in the first place. Mar 5, 2021 · May be my question is not clear I think. As answered in the first question, python has dictionary to do this task. Jan 20, 2016 · 12. In the above example, element=value passes in the value of the value variable to fill in the placeholder with the element. modules[__name__], "clean_%s" % fieldname)() edited Jun 17, 2016 at 19:56. A Dictionary allows us to create a key-value pair for each file where the value is the DataFrame. variable_dict = {} variable_name = "my_variable". getGroup(selected, header+i) On the other hand, if what you actually want is to modify instance Nov 7, 2011 · To support this statement, which could create new variables that are not known at compile time, Python is then forced to access local variables by name within the function, so writing to locals() works. To create a dataframe, the below syntax can be used: pd. It's used to create classes by hand, e. dat" Reading and Writing Files. format(VARIABLE_NAME) = {} The above shown is an illegal operation. Method 1: Using Feb 11, 2022 · Setting instance variables using a setter method. Assuming I want different types of potions (stamina Apr 15, 2024 · Python Variable is containers that store values. Mar 31, 2021 · 1. var1 is 'dynamic input' to program. %resizing empty cells using a loop, arrays can be of different size. This approach will also use the globals() function in addition to the for loop. Ask Question Asked 13 years, Creating a dynamically named function at runtime. # Create main figure. Aug 23, 2023 · Dynamically creating and modifying variables can make the code less clear to other developers. I want to dynamically name the dataframe depending upon the year. Sep 24, 2012 · The string is preceded by an f and the variable is inside the string quotes, surrounded by {}. May 23, 2017 · Every day the algorithm needs to create a pandas dataframe with 2 fixed column names and a column named after every value stored in a dynamic list. Button(root, text=i) They soon find that this does not work. We dynamically create a variable name (variable_name) as a string, and then we store and retrieve its value using the dictionary. Oct 11, 2021 · python: dynamically create and execute existing variable names. my_dict = {} x = "Buffalo" my_dict[x] = 4 I found a similar, but not the same question here Creating dynamically named variables from user input Oct 12, 2013 · Do not try to dynamically name variables. Explore Teams Create a free Team. Python is not “statically typed”. fig = plt. Thanks. Thus: Jul 8, 2017 · For example code creates A {1} to A {10} variables dynamically. A{j} = {}; %creating empty cell. ax = fig. – martineau. figure(1) for k in range(Tot): # add every single subplot to the figure with a for loop. You could use: clusters['cluster_{}'. In the above program, I initially declared an empty dictionary and added the elements into the dictionary. Then create figure and add subplots with a for loop. Oct 21, 2021 · The creation of a dynamic variable name in Python can be achieved with the help of iteration. format() call instead. Result is stored in variable at the end, but I need variable name to be something as data1, data2, data3, etc. write(str(func(i))) Jul 21, 2017 · But the hard part is that I want to dynamically name the args from variables coming from a list or somewhere else. You'll miss out on all the convenient operations that lists and dictionaries provide (think of len (), inserting, removing, sorting, and so on), but it's possible: count = raw_input('Number of variables:') for i in Jul 19, 2023 · DataFrame is the primary data structure of Pandas. Is it possible in c#? Create dynamic variable in c#? and change the variable name in c#? and concatenate the variable name in c# ( like we can concatenate any control id or name ) Feb 29, 2012 · I'm looking for a way to create a dictionary without writing the key explicitly. append([]) 3) Version with lists being a dictionary of lists with numbers as keys (a bit more flexible if you want to remove some of the values later or such): lists[i] = [] About dynamic Jan 25, 2017 · This seems to work if list_all contains strings of the known variables but I don't need the variables obviously, I need the data within those variables. Jan 25, 2017 · This seems to work if list_all contains strings of the known variables but I don't need the variables obviously, I need the data within those variables. dynamic_list = ['variable_1','variable_2'] Using globals scope usually is frown upon as it messies up your namespace and makes it harder to work with the more complex your code is. I'm working on an ajax google maps script and I need to create dynamic variable names in a for loop. loc[org_dataframe['month'] == i] i=i+1 It gives me, SyntaxError: can't assign to operator. To demonstrate this, let's create a dynamic variable using a dictionary and access its value. Normally one would have one object per player which encapsulates all related data. Given a string input, our task is to write a Python program to create a variable from that input (as a variable name) and assign it to some value. 0. Feb 26, 2024 · Using a for loop, it iterates through the original names, converts each name to lowercase, and appends the result to the list lowercase_names. inventory=Inventory() player=Player() healthpotion=Potion("Health potion",player. Here is how we can do that: Create an empty Dictionary. dynamically creating variables in python-1. I came up with three ways to do this in Python. I created the method "read ()" that opens the text file, breaks Jan 1, 2010 · python; dictionary; variables; dynamic; or ask your own question. Below is the sample code I am trying. It doesn't let you define classes with Python's normal class syntax, instead making you set up every class attribute manually. new_df_name = 'df_201612'. Variable names, on the other hand, should be dead simple. Dec 16, 2018 · self. for (var i = 0; i < coords. Jul 30, 2019 · How do you create different variable names while in a loop? [duplicate] (9 answers) 1. json". . So if I have: for x in range(0, 3): Jul 18, 2021 · The problem becomes more complicated when you need to declare variables dynamically in a loop. Oct 20, 2010 · 1. append(x**2) You will get a feel for when you want to use one over the other. Using exec () Method in Python to Convert a Python string to a Variable Name. txt, but the former is a more strict match, and wouldn't match something like fact_or_fiction. Client 1 would be stored in "client_1", Client 2 would be stored in "client_2", etc. Avoid Overwriting Built-in Functions: Be cautious when using the locals() function to dynamically create variables. stamina=100. May 2, 2022 · The other answers are correct to guide you toward collections. Jul 19, 2012 · Is there any way to name a variable with another variable. I would like those instances to have names following the pattern p1, p2, etc: p1 = Point(1,1) p2 = Po Oct 11, 2021 · Now I want to concat the dataframe name (out_df) with a variable user_name which is an input. Apr 18, 2021 · Unless there is an overwhelming need to create a mess of variable names, I would just use a dictionary, where you can dynamically create the key names and associate a value to each. a=eachRow. Sep 25, 2023 · In this example, we use a dictionary (variable_dict) to associate string names with values. Mar 22, 2023 · In other words, watch your casing when creating variables, because Year_Founded will be a different variable than year_founded even though they include the same letters; Variable names that use multiple words in Python should be separated with an underscore _. If I'm understanding your requirements correctly, it sounds like you just want to dynamically assign existing functions new or alternative names -- in which case something along the following lines ought to do the job: import sys. Instead, leverage python's data structures to do what you want. For example, a variable named "site name" should be written as "site_name". write(f'{func(i)}') or f. Apr 13, 2021 · To create a dynamic variable in Python, use a dictionary. I want to create a function that gets the number of variables and creates a dictionary where the variable names are the keys and their values are the variable values. Jul 19, 2016 · I need it to create an instance called 'bar' in the Foo class in this case but I also need to be able to change the 's' variable to any string and for it to still work. var is changed. 3. Having trouble figuring out how to add the column names dynamically: # list on day 1. write(str(a)+"\n") file. I want to read several files json files and write them to a dataframe with a for-loop. i=1 while i<=4: dataframe+str(i)=org_dataframe. list_all = ['list_{num}'. price3 = 45. Happy coding. The arguments are an object, a string and an arbitrary value. name = value. How can I create this type of dynamic variable name in python ? Oct 25, 2010 · To call the function dynamically which is defined in the same module, you can do this way: import sys. Sep 13, 2022 · Python program to create dynamically named variables from user input - GeeksforGeeks. d["group" + str(i)] = self. Jul 6, 2012 · I know how to instantiate a class object from within the code, but how do I create one with a variable name based on user input? Say I prompt the user for a name -- how do I take that info and use it for the variable name of my new object? Just to add why 'dynamically create variable names' is not such a good idea: 'presumably you want to access the variables dynamically as well'. The type() function is used to return the type of the object. iloc is a function, not a dictionary. This will hold our key-value pairs from the For Loop; Start a For Loop using files as our iterator Sep 7, 2012 · Cols - 1 subplots still need location. But player. The advantage is that the file is properly closed after its suite finishes, even if an exception is raised at some point. But one expects lists and dictionaries to demand a little extra thinking. 4. See full list on codingdeeply. I would like to do something like: dict_{}. We will then apply the exec () method with some modifiers and try to convert a string into a variable name. format(num=i) for i in range(3)] print list_all # ['list_0', 'list_1', 'list_2'] So I guess the question is how can I dynamically create and execute python variable names? If don't want to use globals, vars and don't want make a separate module and/or class to encapsulate functions you want to call dynamically, you can call them as the attributes of the current module: import sys. format(i)] = np. String formatting placeholders that use names (such as {element}) are not variables. Dynamic variable names refer to the ability to create variables with names that are not known until runtime. However, I am working with huge amount May 9, 2012 · Because dynamic variable manipulation hides state changes under another layer of obfuscation. This means that you can use these functions to create dynamic variable names by indexing into the dictionaries. Avoid using variable names that are identical to built-in functions or names already used within the scope. A variable is created the moment we first assign a value to it. testcases = [] def testcase(f): """ testcase function decorator """. price2 = 12. That is tom_out_df = out_df. ('button_%d' % i) = tkinter. f'{variable}. Also I want to collect the years in a list which will be used for a later use. Something like this: query = 'SELECT * FROM {}'. However, they get stuck on how to dynamically create those variable names, and may try something like this: for i in range(10): my_calculator. string. DataFrame(data, index, columns, dtypye, copy) This is a general syntax in pandas to create a dataframe. For example. var1=10; for j=1:1:var1. In this example, we will have a variable named by us and an input string. How can I go about defining a new dictionary name every time I need to create one? This is happening in a for loop, so I need to use dynamic dict names. The exec can be out of the code path that is executed. format(i) output = pd. modules[__name__] def foo(): msg="I'm called dynamically!" return msg. If you must use a string (for example if the name of the class is created dynamically), then you will need to use other techniques. Conclusion And there, we have a cool way to dynamically create variables May 29, 2014 · You probably want a dict instead of separate variables. python-3. file. health remains unchanged, only healthpotion. add_subplot(Rows,Cols,Position[k]) ax. pyspark. This approach allows us to mimic variable names with string keys. Using a dynamic variable name, as an argument for a function/method. It's all quoted from mhawke: You can't use parameter substitution for the table name. Use a formatted string literal to create a file name using variables, e. Mutate Variables with String Names (Python) 2. g. var marker+i = "some stuff"; } What I want to get is: marker0, marker1, marker2 and so on. This is the best way, I know of to create dynamic variables in python. com How do I create variable variables? (18 answers) Closed 5 years ago. If the program requires arbitrary variable "names," a dictionary is the best choice, as explained in other answers. Aug 23, 2023 · As a result, the output “Hello, dynamic world!” is printed to the console. Jul 24, 2021 · The best way to solve your problem is to save the values in an array and access then via indices, rather than creating separate variables for each element in the array. f"file_{i}. cx bh vi ey al tm de uq jz fw