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Creating python dictionaries using for loop

I make a bunch of matrices that I want to store in python dictionaries and I always find myself typing the same thing for every state that I want to build, i.e.
Ne21_1st_state = {}
Ne21_2nd_state = {}
Ne21_3rd_state = {}
Ne21_4th_state = {}
Ne21_5th_state = {}
Ne21_6th_state = {}
...
Ne21_29th_state = {}
Ne21_30th_state = {}
Can somebody help me automate this using python for loops?
Thanks in advance!
I want something like this:
for i in range(3, 11):
states = f'Ar36_{i}th_state'
print(states)
where the output would be:
Ar36_3th_state
Ar36_4th_state
Ar36_5th_state
Ar36_6th_state
Ar36_7th_state
Ar36_8th_state
Ar36_9th_state
Ar36_10th_state
but instead of printing it it would create individual dictionaries named Ar36_3th_state, Ar36_4th_state, Ar36_5th_state, ...

can't we make a List of dictionaries
List of 30 (or any N) elements where each element is a dictionary with key = "Ar36_{i}th_state" and value = {whatever value you want}

You can create "name" of pseudo variable and use it as key in dictionary like:
my_dic = {1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e'}
my_empty_dic = {}
solution = {}
for i in range(1, 31):
name = 'Ne21_'+str(i)+'st_state'
#solution[name] = my_dic
solution[name] = my_empty_dic
for pseudo_variable in solution:
print(pseudo_variable, solution[pseudo_variable])
print(solution['Ne21_16st_state'])
for pseudo_variable in solution:
if '_16st' in pseudo_variable:
print(pseudo_variable, solution[pseudo_variable])

One way I've done this is using list comprehension.
key = list(
str(input(f"Please enter a Key for value {x + 1}: "))
if x == 0
else str(input(f"\nPlease enter a Key for value {x + 1}: "))
for x in range(3))
value = list(str(input(f"\nPlease enter a Bool for value {x + 1}: "))
for x in range(3))
BoolValues = dict(zip(key, value))
I first create a list of keys followed by a list of the values to be stored in the keys. Then I just zip them together into a dictionary. The conditional statements in the first list are only for a slightly better user-experience with \n being added if it's passed the first input.
Actually now that I look back on the question it may be slightly different to what I was thinking, are you trying to create new dictionaries for every matrix? If that is the case, is it something similar to this?: How do you create different variable names while in a loop?

How to check a list for duplicates and add values if there are any?

I'm totally beginner with coding and just need help with some stuff.
My dream was to write a smart shopping list that automatically detects duplicates and increases the weight of duplicate products.
I get the shopping list from an external file which has the following form:
weight\n
ingredient\n
eg.
60
eggs
120
beef meat
25
pasta
120
eggs
etc...
After converting this files to dictionaries by this code:
final_list = []
def get_list(day_list):
for day in range(len(day_list)):
day += 1
day_to_open = f'Days/day{str(day)}.txt'
with open(day_to_open, 'r') as file:
day1 = file.readlines()
day1 = [item.rstrip() for item in day1]
x = 0
y = 1
list = []
for item in range(0, len(day1), 2):
dictio = {day1[y]: day1[x]}
x += 2
y += 2
list.append(dictio)
final_list.append(list)
list = []
for item in final_list:
list += item
return list
days = [1, 2, 3]
list = get_list(day_list=days)
Finally I get list of dictionaries like that:
[{'eggs': '60'}, {'beef meat': '120'}, {'pasta': '25'}, {'eggs': '120'}]
How can I iterate through the dictionary to check if any products are repeating, and if so leave one with the added weight?
For three weeks I have been trying to solve it, unfortunately to no avail.
Thank you very much for all your help!
#Edit
my goal is to make it look like this:
[{'eggs': 180}, {'beef meat': 120}, {'pasta': 25}]
#egg weight added (120 + 60)#

lis = [{'eggs': '60'}, {'beef meat': '120'}, {'pasta': '25'}, {'eggs': '120'}]
# make 1 dict from list of dicts and update max value
new = {}
for d in lis:
for k, v in d.items():
if (k not in new) or (int(v) > int(new[k])):
new[k] = v
# rebuild list of dicts
lis = [{k:v} for k, v in new.items()]
print(lis)
# [{'eggs': '120'}, {'beef meat': '120'}, {'pasta': '25'}]

As ShadowRanger has pointed out, it's not common practice to have a list of multiple dictionaries as you have done. Dictionaries are very useful if used correctly.
I'm not entirely sure the structure of the files you are reading, so I will just explain a way forward and leave it up to you to implement it. What I would suggest is that you first initiate a dictionary with all the necessary keys (ingredients in your case) with each of the values set to 0 (as an integer or float, rather than a string), so you would get a dictionary like this:
shopping_list = {'eggs': 0, 'beef meat': 0, 'pasta': 0}
Then, you will be able to access each of the values by calling the shopping_list dictionary and specifying the key of interest. For example, if you wanted to print the value of eggs, you would write:
print(shopping_list['eggs']) # this would return 0
You can then easily increase/decrease a value of interest; for example, to add 10 to pasta, you would write:
shopping_list['eggs'] += 10
Using this method, you can then iterate through each of your items, select the ingredient of interest and add the weight. So if you have duplicates, it will just add to the same ingredient. Again, I'm not sure the structure of the files you are reading, but it would be something along the lines of:
for ingredient, weight in file:
shopping_list[ingredient] += weight
Good luck for your dream - all the best!

Python 3: Creating list of multiple dictionaries have same keys but different values coming from multiple lists

I'm parsing through a response of XML using xpath from lxml library.
I'm getting the results and creating lists out of them like below:
object_name = [o.text for o in response.xpath('//*[name()="objectName"]')]
object_size_KB = [o.text for o in response.xpath('//*[name()="objectSize"]')]
I want to use the lists to create a dictionary per element in list and then add them to a final list like this:
[{'object_name': 'file1234', 'object_size_KB': 9347627},
{'object_name': 'file5671', 'objeobject_size_KBt_size': 9406875}]
I wanted a generator because I might need to search for more metadata from the response in the future so I want my code to be future proof and reduce repetition:
meta_names = {
'object_name': '//*[name()="objectName"]',
'object_size_KB': '//*[name()="objectSize"]'
}
def parse_response(response, meta_names):
"""
input: response: api xml response text from lxml xpath
input: meta_names: key names used to generate dictionary per object
return: list of objects dictionary
"""
mylist = []
# create list of each xpath match assign them to variables
for key, value in meta_names.items():
mylist.append({key: [o.text for o in response.xpath(value)]})
return mylist
However the function gives me this:
[{'object_name': ['file1234', 'file5671']}, {'object_size_KB': ['9347627', '9406875']}]
I've been searching for a similar case in the forums but couldn't find something to match my needs.
Appreciate your help.
UPDATE: Renneys answer was what I wanted I just adjusted the length value of range of my results since I don't always have the same length of xpath per object key and since my lists have identical length everytime I picked first index [0].
now the function looks like this.
def create_entries(root, keys):
tmp = []
for key in keys:
tmp.append([o.text for o in root.xpath('//*[name()="' + key + '"]')])
ret = []
# print(len(tmp[0]))
for i in range(len(tmp[0])):
add = {}
for j in range(len(keys)):
add[keys[j]] = tmp[j][i]
ret.append(add)
return ret

Use a two dimensional array:
def createEntries(root, keys):
tmp = []
for key in keys:
tmp.append([o.text for o in root.xpath('//*[name()="' + key + '"]')])
ret = []
for i in range(len(tmp)):
add = {}
for j in range(len(keys)):
add[keys[j]] = tmp[j][i]
ret.append(add)
return ret

I think this is what you are looking for.
You can use zip to combine your two lists into a list of value pairs.
Then, you can use a list comprehension or a generator expression to pair your value pairs with your desired keys.
import pprint
object_name = ['file1234', 'file5671']
object_size = [9347627, 9406875]
[{'object_name': 'file1234', 'object_size_KB': 9347627},
{'object_name': 'file5671', 'objeobject_size_KBt_size': 9406875}]
[{'object_name': ['file1234', 'file5671']}, {'object_size_KB': ['9347627', '9406875']}]
# List Comprehension
obj_list = [{'object_name': name, 'object_size': size} for name,size in zip(object_name,object_size)]
pprint.pprint(obj_list)
print('\n')
# Generator Expression
generator = ({'object_name': name, 'object_size': size} for name,size in zip(object_name,object_size))
for obj in generator:
print(obj)
Live Code Example -> https://onlinegdb.com/SyNSwd7jU
I think the accepted answer is more efficient, but here's an example of how list comprehensions could be used.
meta_names = {
'object_name': ['file1234', 'file5671'],
'object_size_KB': ['9347627', '9406875'],
'object_text': ['Bob', 'Ross']
}
def parse_response(meta_names):
"""
input: response: api xml response text from lxml xpath
input: meta_names: key names used to generate dictionary per object
return: list of objects dictionary
"""
# List comprehensions
to_dict = lambda l: [{key:val for key,val in pairs} for pairs in l]
objs = list(zip(*list([[key,val] for val in vals] for key,vals in meta_names.items())))
pprint.pprint(to_dict(objs))
parse_response(meta_names)
Live Code -> https://onlinegdb.com/ryLq4PVjL

How to structure dictionary to apply to function with enumerate

I am trying to re-build a simple function, that ask for a dictionary as an input. No matter what I try I cannot figure out a minimum working example of a dictionary to pass through this function. I've read upon dictionaries and there is not so much room to create it differently, hence I do not know what the problem is.
I've tried to apply following minimum dictionary examples:
import nltk
#Different dictionaries to try as minimum working examples:
comments1 = {1 : 'Rockies', 2: 'Red Sox'}
comments2 = {'key1' : 'Rockies', 'key2': 'Red Sox'}
comments3 = dict([(1, 3), (2, 3)])
#Function:
def tokenize_body(comments):
tokens = {}
for idx, com_id in enumerate(comments):
body = comments[com_id]['body']
tokenized = [x.lower() for x in nltk.word_tokenize(body)]
tokens[com_id] = tokenized
return tokens
tokens = tokenize_body(comments1)
I know that with enumerate I am basically calling the index and the key, I can not figure out how to call the 'body', i.e the strings that I want to tokenize.
For both comments1 and comments2 with strings as inputs I receive the error: TypeError: string indices must be integers.
If I apply integers instead of strings, comments3, I receive the error:
TypeError: 'int' object is not subscriptable.
This may seem trivial to you, but I can not figure out what I am doing wrong. If you could provide a minimum working example, that would be highly appreciated.

In order to loop through a dictionary in python, you need to use the items method to get both keys and values:
comments = {"key1": "word", "key2": "word2"}
def tokenize_body(comments):
tokens = {}
for key, value in comments.items():
# values - word, word2
# keys - key1, key2
tokens[key] = [x.lower() for x in nltk.word_tokenize(value)]
return tokens
enumerate is used for lists, in order to get the index of an element:
l = ['a', 'b']
for index, elm in enumerate(l):
print(index) # => 0, 1

You might be looking for .items(), e.g.:
for idx, item in enumerate(comments1.items()):
print(idx, item)
This will print
0 (1, 'Rockies')
1 (2, 'Red Sox')
See a demo on ideone.com.

Append several variables to a list in Python

I want to append several variables to a list. The number of variables varies. All variables start with "volume". I was thinking maybe a wildcard or something would do it. But I couldn't find anything like this. Any ideas how to solve this? Note in this example it is three variables, but it could also be five or six or anything.
volumeA = 100
volumeB = 20
volumeC = 10
vol = []
vol.append(volume*)

You can use extend to append any iterable to a list:
vol.extend((volumeA, volumeB, volumeC))
Depending on the prefix of your variable names has a bad code smell to me, but you can do it. (The order in which values are appended is undefined.)
vol.extend(value for name, value in locals().items() if name.startswith('volume'))
If order is important (IMHO, still smells wrong):
vol.extend(value for name, value in sorted(locals().items(), key=lambda item: item[0]) if name.startswith('volume'))

Although you can do
vol = []
vol += [val for name, val in globals().items() if name.startswith('volume')]
# replace globals() with locals() if this is in a function
a much better approach would be to use a dictionary instead of similarly-named variables:
volume = {
'A': 100,
'B': 20,
'C': 10
}
vol = []
vol += volume.values()
Note that in the latter case the order of items is unspecified, that is you can get [100,10,20] or [10,20,100]. To add items in an order of keys, use:
vol += [volume[key] for key in sorted(volume)]

EDIT removed filter from list comprehension as it was highlighted that it was an appalling idea.
I've changed it so it's not too similar too all the other answers.
volumeA = 100
volumeB = 20
volumeC = 10
lst = map(lambda x : x[1], filter(lambda x : x[0].startswith('volume'), globals().items()))
print lst
Output
[100, 10, 20]

do you want to add the variables' names as well as their values?
output=[]
output.append([(k,v) for k,v in globals().items() if k.startswith('volume')])
or just the values:
output.append([v for k,v in globals().items() if k.startswith('volume')])

if I get the question appropriately, you are trying to append different values in different variables into a list. Let's see the example below.
Assuming :
email = 'example#gmail.com'
pwd='Mypwd'
list = []
list.append(email)
list.append (pwd)
for row in list:
print(row)
# the output is :
#example#gmail.com
#Mypwd
Hope this helps, thank you.