python create variable in loop - Brave Search

How do you create different variable names while in a loop? [duplicate]

stackoverflow.com › questions › 6181935 › how-do-you-create-different-variable-names-while-in-a-loop

Sure you can; it's called a dictionary:

d = {}
for x in range(1, 10):
    d["string{0}".format(x)] = "Hello"

>>> d["string5"]
'Hello'
>>> d
{'string1': 'Hello',
 'string2': 'Hello',
 'string3': 'Hello',
 'string4': 'Hello',
 'string5': 'Hello',
 'string6': 'Hello',
 'string7': 'Hello',
 'string8': 'Hello',
 'string9': 'Hello'}

I said this somewhat tongue in check, but really the best way to associate one value with another value is a dictionary. That is what it was designed for!

Answer from the wolf on Stack Overflow

stackoverflow.com › questions › 6181935 › how-do-you-create-different-variable-names-while-in-a-loop

python - How do you create different variable names while in a loop? - Stack Overflow

Sure you can; it's called a dictionary:

d = {}
for x in range(1, 10):
    d["string{0}".format(x)] = "Hello"

>>> d["string5"]
'Hello'
>>> d
{'string1': 'Hello',
 'string2': 'Hello',
 'string3': 'Hello',
 'string4': 'Hello',
 'string5': 'Hello',
 'string6': 'Hello',
 'string7': 'Hello',
 'string8': 'Hello',
 'string9': 'Hello'}

I said this somewhat tongue in check, but really the best way to associate one value with another value is a dictionary. That is what it was designed for!

It is really bad idea, but...

for x in range(0, 9):
    globals()['string%s' % x] = 'Hello'

and then for example:

print(string3)

will give you:

Hello

However this is bad practice. You should use dictionaries or lists instead, as others propose. Unless, of course, you really wanted to know how to do it, but did not want to use it.

reddit.com › r/learnpython › is it possible to create variables in a loop?

r/learnpython on Reddit: Is it possible to create variables in a loop?

June 10, 2022 -

I need to create a large number of variable. Currently what I have is:

var1 = 0
var2 = 0
...
var1000 = 0

Is it possible to create these variables in some sort of loop instead of writing each one?

#Pseudocode

for i in range(1000):
    var_i = 0

Update:

Thanks a lot for all the comments! The list idea worked!

You can create a dictionary or a list to save and easily access all these: # dictionary d = {} for i in range(1, 1000): d["var{0}".format(i)] = 0 # list var = [] for i in range(1, 1000): var.append(0)

No. And you don't ever need to do this. Use a list or a dictionary.

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discuss.python.org › python help

Creating new variables inside a for loop - Python Help - Discussions on Python.org

June 10, 2024 - Hello! I am a relatively new python user with little experience in for loops, and one is definitely necessary for my project. I have a pandas dataframe that looks like this: And I need to “integrate” the accel columns their respective velocity (and eventually position) and the angular into ...

quora.com › How-do-I-create-a-loop-that-creates-variables-in-Python

How to create a loop that creates variables in Python - Quora

Answer (1 of 6): You don’t. Now I know someone will come along with a solution involving locals(), but then to use those ‘variables’ in your code you would need use ‘locals()’. Misusing locals() especially writing to it is a sign of a bad design. It is far simpler just to add items ...

reddit.com › r/learnpython › is it possible to create variables using a loop?

r/learnpython on Reddit: Is it possible to create variables using a loop?

January 15, 2023 -

You're probably why I would want to do this but I'm just wondering.

Say I have

for num in range (1, 4):
    f"created_variable_{num}" = num

It would create 4 variables (if it worked):

created_variable_1 = 1

created_variable_2 = 2

created_variable_3 = 3

But it doesn't. Is there a recommended way to create variables using a loop correctly?

https://www.reddit.com/r/learnpython/wiki/faq#wiki_how_do_i_make_variable_variables.3F Ok, it's technically possible to do this, but it's bad style and leads to bugs. You should use a container like a dictionary or list instead. Keeping them in a neat container also gives you the advantage of being able to loop over all your elements.

Use a dictionary: created_variables = {} for num in range (1, 4): created_variables[num] = num print(created_variables[1]) # 1 Although in this case, it may make more sense to use a list since the keys are contiguous numbers that are almost starting at 0.

Imperialcollegelondon

imperialcollegelondon.github.io › python-novice-mix › 07-for-loops › index.html

Programming in Python: For Loops

November 8, 2018 - Not a list: the numbers are produced on demand to make looping over large ranges more efficient. ... Initialize an accumulator variable to zero, the empty string, or the empty list.

sololearn.com › en › Discuss › 2862156 › how-to-make-a-loop-that-creates-variables-automatically-in-python

How to make a loop that creates variables automatically... ...

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askubuntu.com › questions › 748006 › python-create-variables-using-loop

bash - Python: create variables using loop - Ask Ubuntu

In Python, you can use the exec() function:

>>> for i in range(1, 6):
...     exec("line_dict_%s = { 'a': 1 }" % i)
... 
>>> line_dict_1
{'a': 1}
>>> line_dict_2
{'a': 1}
>>> line_dict_3
{'a': 1}
>>> line_dict_4
{'a': 1}
>>> line_dict_5
{'a': 1}

Using exec() is not a good idea most of the times, i would rather prefer a dictionary to keep the mappings:

>>> kv = {}
>>> for i in range(1, 6):
...     kv['line_dict_{}'.format(i)] = { 'a': 1 }
... 
>>> kv
{'line_dict_4': {'a': 1}, 'line_dict_5': {'a': 1}, 'line_dict_1': {'a': 1}, 'line_dict_3': {'a': 1}, 'line_dict_2': {'a': 1}}

>>> kv['line_dict_1']
{'a': 1}
>>> kv['line_dict_2']
{'a': 1}
>>> kv['line_dict_3']
{'a': 1}
>>> kv['line_dict_4']
{'a': 1}
>>> kv['line_dict_5']
{'a': 1}

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daniweb.com › programming › software-development › threads › 242283 › define-a-variable-inside-for-loop

python - define a variable inside for loop [SOLVED] | DaniWeb

November 30, 2009 - For example I have a loop with 10 steps, and i want to define 10 variable: x1, x2, x3....x10 and then print them out: x1=something, x2=something, ......, x10=something.Does anyone know how to do this? ... Creating variables named x1, x2, ... is brittle and hard to maintain. In Python, prefer a sequence or mapping and derive the label at print time.

plainenglish.io › home › blog › python › how to dynamically declare variables inside a loop in python

How to Dynamically Declare Variables Inside a Loop in Python

July 18, 2021 - In the above program, I initially ... elements into the dictionary. I used string concatenation method to declare dynamic variables like x1, x2, x3……. . Then I assumed the values from the for loop to the dynamic variables. The dictionary will look like · {‘x0’: 0, ‘x1’: 1, ‘x2’: 2, ‘x3’: 3, ‘x4’: 4, ‘x5’: 5, ‘x6’: 6, ‘x7’: 7, ‘x8’: 8, ‘x9’: 9} You can learn about dictionaries here. Python ...

python.plainenglish.io › how-to-dynamically-declare-variables-inside-a-loop-in-python-21e6880aaf8a

How to Dynamically Declare Variables Inside a Loop in Python | by Naveenkumar M | Python in Plain English

August 9, 2024 - . Then I assumed the values from the for loop to the dynamic variables. The dictionary will look like · {‘x0’: 0, ‘x1’: 1, ‘x2’: 2, ‘x3’: 3, ‘x4’: 4, ‘x5’: 5, ‘x6’: 6, ‘x7’: 7, ‘x8’: 8, ‘x9’: 9} You can learn about dictionaries here. ... Finally, I iterated over the dictionary and separated the keys into a standalone variable using the exec command. The exec command executes the Python code inside it.

quora.com › How-do-you-create-different-variable-names-while-in-a-loop-in-Python

How to create different variable names while in a loop in Python - Quora

Answer (1 of 5): There is a way: [code]>>> exec("A = 3") >>> A 3 [/code]… meaning in a for loop you could synthesize some varnames and make them globals. However said practice is heavily frowned upon. Best practice is to create a dict and instead of a plethora of names polluting your namespace,...

python-forum.io › thread-23500.html

Changing a variable's name on each iteration of a loop

Is it possible in python to change the name of a variable on each iteration of a loop? For example: for i in range(10): variableNameToChange+i='iterationNumber=='+str(i)I know this won't work, and you can't assign to an operator, but how would y...

delftstack.com › home › howto › python › python dynamic variable name

Python Dynamic Variable Name | Delft Stack

December 14, 2023 - When combined with the globals() function, which provides access to the global symbol table as a dictionary, you can dynamically create variables. In the following example, we will use the for loop to iterate over a range of numbers. Inside the loop, we will create dynamic variables using the globals() function...

infoworld.com › home › software development › programming languages › python

How to use the Python for loop | InfoWorld

August 7, 2021 - A container, sequence, or generator that contains or yields the elements to be looped over. In general, any object that supports Python’s iterator protocol can be used in a for loop. A variable that holds each element from the container/sequence/generator.

stackoverflow.com › questions › 26668642 › creating-variables-in-loop-and-initialize-them-in-python

arrays - Creating variables in loop and initialize them in Python - Stack Overflow

You can use locals() and globals() to dynamically assign variables.

>>> param = range(10)
>>> var = 'abcdefghij'
>>> locals().update({'{}_true'.format(k): v for k, v in zip(var, param)})
>>> c_true
2
>>> f_true
5

It was already discussed here:

Using a string variable as a variable name

In particular, something like this should work:

for k, v in zip(gvalues, params):
    exec('%s = %s' % (k, v))

stackoverflow.com › questions › 13603215 › using-a-loop-in-python-to-name-variables

Using a loop in Python to name variables - Stack Overflow

Use a dictionary instead. E.g:

doubles = dict()

for x in range(1, 13):
    doubles[x] = x * 2

Or if you absolutely must do this AND ONLY IF YOU FULLY UNDERSTAND WHAT YOU ARE DOING, you can assign to locals() as to a dictionary:

>>> for x in range(1, 13):
...     locals()['double_{0}'.format(x)] = x * 2
... 
>>> double_3
6

There never, ever should be a reason to do this, though - since you should be using the dictionary instead!

expanding my comment: "use a dict. it is exactly why they were created"

using defaultdict:

>>> from collections import defaultdict
>>> d = defaultdict(int)

using normal dict:

>>> d = {}

the rest:

>>> for x in range(1, 13):
    d['double_%02d' % x] = x * 2


>>> for key, value in sorted(d.items()):
    print key, value


double_01 2
double_02 4
double_03 6
double_04 8
double_05 10
double_06 12
double_07 14
double_08 16
double_09 18
double_10 20
double_11 22
double_12 24

support.gurobi.com › hc › en-us › community › posts › 12638796384529-Create-variables-in-a-loop

Create variables in a loop – Gurobi Help Center

if x != y then z=0 (x,y and z are binary variables) and if x==y then z can be 0 or 1. I read in this link that I need an auxiliary binary variable and then use indicator constraints.

stackoverflow.com › questions › 11319909 › creating-new-variables-in-loop-with-names-from-list-in-python

python - How can I create new variables in a loop, with the names and values coming from a list? - Stack Overflow

I think dictionaries are more suitable for this purpose:

>>> name = ['mike', 'john', 'steve']   

>>> age = [20, 32, 19] 

>>> dic=dict(zip(name, age))

>>> dic['mike']
20
>>> dic['john']
32

But if you still want to create variables on the fly you can use globals()[]:

>>> for x,y in zip(name, age):
    globals()[x] = y


>>> mike
20
>>> steve
19
>>> john
32

You can use globals():

globals()[e] = age[index]

Generally, though, you don't want to do that; a dictionary is much more convenient.

people = {
    'mike': 20,
    'john': 32,
    'steve': 19
}

discuss.python.org › python help

Is it possible to write a loop that includes variables from a list? - Python Help - Discussions on Python.org

July 27, 2023 - Hi all, please bear with me as i’m fairly new to Python. I have a working python script that does the following: Opens a csv file Edits the csv (removes first row, adds a column, data-fills column) Exports the csv with new name The source csv, new column name, and exported csv name are defined by variables.