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Python - parsing and updating json

I'm able to load and parse a json file with Python by referring to list items by name. My users.json data file:
{
"joe": {
"secret": "abc123.321def"
},
"sarah": {
"secret": "led789.321plo"
},
"dave": {
"secret": "ghi532.765dlmn"
}
}
My code - to output the 'secret' value associated with a specific user (e.g. Dave):
import json
with open('users_sample.json') as f:
users = json.load(f)
# f.close()
print(users['dave']['secret'])
This outputs Dave's secret:
ghi532.765dlmn
That's easy enough when I can predict or know the user names, but how do I iterate through each user in the users.json file and output each user's 'secret' value?
Thanks in advance!

I would encapsulate the logic to print each user and their associated function into a helper function:
def print_users(users_dict: dict, header='Before'):
print(f'-- {header}')
for u in users_dict:
print(f' {u}: {users_dict[u].get("secret", "<empty>")}')
Then, upon loading the users object initially via json.load, you can then call the function like so:
print_users(users)
To replace the secret for each user, in this case to replace every occurrence of a dot . with a plus +, a simple approach could be to use a for loop to update the users object in place:
for name, user in users.items():
if 'secret' in user:
user['secret'] = user['secret'].replace('.', '+')
Then print the result after the replacements are carried out:
print_users(users, 'After')
Finally, we can write the result users object back out to a file:
with open('users_sample_UPDATED.json', 'w') as out_file:
json.dump(users, out_file)
The output of the above code, in this case would be:
-- Before
joe: abc123.321def
sarah: led789.321plo
dave: ghi532.765dlmn
-- After
joe: abc123+321def
sarah: led789+321plo
dave: ghi532+765dlmn
The full code:
import json
def main():
with open('users_sample.json') as f:
users = json.load(f)
print_users(users)
new_users = {name: {'secret': user['secret'].replace('.', '+')}
for name, user in users.items()}
print_users(new_users, 'After')
with open('users_sample_UPDATED.json', 'w') as out_file:
json.dump(new_users, out_file)
def print_users(users_dict: dict, header='Before'):
print(f'-- {header}')
for u in users_dict:
print(f' {u}: {users_dict[u].get("secret", "<empty>")}')
if __name__ == '__main__':
main()

Iterate the dictionary using a for loop
code that works:
import json
with open('users_sample.json') as f:
users = json.load(f)
for user in users:
print(f"user name: {user} secret: {users[user]['secret']}")

You have a nested dictionary - i.e., each value associated with a top-level key is also a dictionary. You can iterate over those dictionaries with the built-in values() function. This leads to:
print(*[e.get('secret') for e in users.values()], sep='\n')

How to refer to a dictionary using input string that is name of dictionary

I write a code that creates the list of purchases in excel (shows
price, name of each product and shows total price in the end).
For example it gets a some number of strings that are also dictionary names.
And it creates an excel file with a list of purchases, their price,
and total price at the end.
I don't know what Dictionary it will be but I want to get a price
which is a key pair.
Code:
import openpyxl as xl
Milk = {
"name": "Milk",
"price": 1,
"id": "01",
}
Chicken = {
"name": "Chicken",
"price": 5,
"id": "02"
}
wb = xl.load_workbook('List.xlsx')
sheet = wb['Лист1']
command = ''
num = int(input())
for row in range(2,num):
command = input()
value = command
command = sheet.cell(row,1)
command.value = value
command = sheet.cell(row,2)
key = 'price'
command.value = command.get("price")
wb.save('transactions3.xlsx')

I guess what you might be looking for is locals(), which keeps, among others, the available variables in the local scope, see this post.
my_dict = {'apples': 4}
# assume user input is `my_dict`
dict_name = input()
# return the dictionary's values
print(locals()[dict_name])
Just as a side note, instead of using openpyxl, I would recommend to use pandas dataframes, which implement .to_csv and .from_csv and to me is much more user friendly.

Access one item from a dict and store it into a variable

I am trying to get all the "uuid"'s from an API, and the issue is that it is stored into a dict (I think). Her is how it looks on the API:
{"guild": {
"_id": "5eba1c5f8ea8c960a61f38ed",
"name": "Creators Club",
"name_lower": "creators club",
"coins": 0,
"coinsEver": 0,
"created": 1589255263630,
"members":
[{ "uuid": "db03ceff87ad4909bababc0e2622aaf8",
"rank": "Guild Master",
"joined": 1589255263630,
"expHistory": {
"2020-06-01": 280,
"2020-05-31": 4701,
"2020-05-30": 0,
"2020-05-29": 518,
"2020-05-28": 1055,
"2020-05-27": 136665,
"2020-05-26": 34806}}]
}
}
Now I am interested in the "uuid" part there, and take note: There is multiple players, it can be 1 to 100 players, and I am going to need every UUID.
Now I have done this in my python to get the UUID's displayed on the website:
try:
f = requests.get(
"https://api.hypixel.net/guild?key=[secret]&id=" + guild).json()
guildName = f["guild"]["name"]
guildMembers = f["guild"]["members"]
members = client.getPlayer(uuid=guildMembers) #this converts UUID to player names
#I need to store all uuid's in variables and put them at "guildMembers"
And that gives me all the "UUID codes", and I will be using client.getPlayer(uuid=---) to convert the UUID into the Player Names. I have to loop through each "UUID" into that code client.getPlayer(uuid=---) . But first of I need to save the UUID'S in variables, I have been doing members.uuid to access the UUID on my HTML file, but I don't know how you do the .uuid part in python
If you need anything else, just comment :)

List comprehension is a powerful concept:
members = [client.getPlayer(member['uuid']) for member in guildMembers]
Edit:
If you want to insert the names back into your data (in guildMembers),
use a dictionary comprehension with {uuid: member_name,} format:
members = {member['uuid']: client.getPlayer(uuid=member['uuid']) for member in guildMembers}
Than you can update guildMembers with your results:
for member in guildMembers:
guildMembers[member]['name'] = members[member['uuid']]

Assuming that guild is the main dictionary in which a key called members exists with a list of "sub dictionaries", you can try
uuid = list()
for x in guild['members']:
uuid.append(x['uuid'])
uuid now has all the uuids

If i understood situation right, You just need to loop through all received uuids and get players' data. Something like this:
f = requests.get("https://api.hypixel.net/guild?key=[secret]&id=" + guild).json()
guildName = f["guild"]["name"]
guildMembers = f["guild"]["members"]
guildMembersData = dict() # Here we will save member's data from getPlayer method
for guildMember in guildMembers:
uuid = guildMember["uuid"]
memberData = client.getPlayer(uuid=uuid)
guildMembersData[uuid] = client.getPlayer(uuid=guildMember["uuid"])
print(guildMembersData) # Here will be players' Data.

Parsing json file to collect data and store in a list/array

I am trying to build an IOT setup. I am thinking of using a json file to store states of the sensors and lights of the setup.
I have created a function to test out my concept. Here is what I wrote so far for the data side of things.
{
"sensor_data": [
{
"sensor_id": "302CEM/lion/light1",
"sensor_state": "on"
},
{
"sensor_id": "302CEM/lion/light2",
"sensor_state": "off"
}
]
}
def read_from_db():
with open('datajson.json') as f:
data = json.load(f)
for sensors in data['sensor_data']:
name = sensors['sensor_id']
read_from_db()
What I want to do is to parse the sensor_id into an array so that I can access them by saying for example sensor_name[0]. I am not sure how to go about it. I tried array.array but it doesn't save any values, have also tried .append but not the result I expected. Any suggestions?

If I understood correctly, all you have to do is assign all those sensors to names using a for loop and then return the result:
import json
def read_from_db():
with open('sensor_data.json') as f:
data = json.load(f)
names = [sensors['sensor_id'] for sensors in data['sensor_data']]
return names
sensor_names = read_from_db()
for i in range(len(sensor_names)):
print(sensor_names[i])
This will print:
302CEM/lion/light1
302CEM/lion/light2

Writing JSON data in python. Format

I have this method that writes json data to a file. The title is based on books and data is the book publisher,date,author, etc. The method works fine if I wanted to add one book.
Code
import json
def createJson(title,firstName,lastName,date,pageCount,publisher):
print "\n*** Inside createJson method for " + title + "***\n";
data = {}
data[title] = []
data[title].append({
'firstName:', firstName,
'lastName:', lastName,
'date:', date,
'pageCount:', pageCount,
'publisher:', publisher
})
with open('data.json','a') as outfile:
json.dump(data,outfile , default = set_default)
def set_default(obj):
if isinstance(obj,set):
return list(obj)
if __name__ == '__main__':
createJson("stephen-king-it","stephen","king","1971","233","Viking Press")
JSON File with one book/one method call
{
"stephen-king-it": [
["pageCount:233", "publisher:Viking Press", "firstName:stephen", "date:1971", "lastName:king"]
]
}
However if I call the method multiple times , thus adding more book data to the json file. The format is all wrong. For instance if I simply call the method twice with a main method of
if __name__ == '__main__':
createJson("stephen-king-it","stephen","king","1971","233","Viking Press")
createJson("william-golding-lord of the flies","william","golding","1944","134","Penguin Books")
My JSON file looks like
{
"stephen-king-it": [
["pageCount:233", "publisher:Viking Press", "firstName:stephen", "date:1971", "lastName:king"]
]
} {
"william-golding-lord of the flies": [
["pageCount:134", "publisher:Penguin Books", "firstName:william","lastName:golding", "date:1944"]
]
}
Which is obviously wrong. Is there a simple fix to edit my method to produce a correct JSON format? I look at many simple examples online on putting json data in python. But all of them gave me format errors when I checked on JSONLint.com . I have been racking my brain to fix this problem and editing the file to make it correct. However all my efforts were to no avail. Any help is appreciated. Thank you very much.

Simply appending new objects to your file doesn't create valid JSON. You need to add your new data inside the top-level object, then rewrite the entire file.
This should work:
def createJson(title,firstName,lastName,date,pageCount,publisher):
print "\n*** Inside createJson method for " + title + "***\n";
# Load any existing json data,
# or create an empty object if the file is not found,
# or is empty
try:
with open('data.json') as infile:
data = json.load(infile)
except FileNotFoundError:
data = {}
if not data:
data = {}
data[title] = []
data[title].append({
'firstName:', firstName,
'lastName:', lastName,
'date:', date,
'pageCount:', pageCount,
'publisher:', publisher
})
with open('data.json','w') as outfile:
json.dump(data,outfile , default = set_default)

A JSON can either be an array or a dictionary. In your case the JSON has two objects, one with the key stephen-king-it and another with william-golding-lord of the flies. Either of these on their own would be okay, but the way you combine them is invalid.
Using an array you could do this:
[
{ "stephen-king-it": [] },
{ "william-golding-lord of the flies": [] }
]
Or a dictionary style format (I would recommend this):
{
"stephen-king-it": [],
"william-golding-lord of the flies": []
}
Also the data you are appending looks like it should be formatted as key value pairs in a dictionary (which would be ideal). You need to change it to this:
data[title].append({
'firstName': firstName,
'lastName': lastName,
'date': date,
'pageCount': pageCount,
'publisher': publisher
})