Not getting expected output in python when converting a csv to json - python

I have an excel file in which data is saved in csv format in such a way.This data is present in the excel file as shown below,under column A (The CSV File is generated by LabView Software code which i have written to generate data).I have also attached an image of the csv file for reference at the end of my question.
RPM,Load Current,Battery Output,Power Capacity
1200,30,12,37
1600,88,18,55
I want to create a Json file in such format
{
"power_capacity_data" :
{
"rpm" : ["1200","1600"],
"load_curr" : ["30","88"],
"batt_output" : ["12","18"],
"power_cap" : ["37","55"]
}
}
This is my code
import csv
import json
def main():
#created a dictionary so that i can append data to it afterwards
power_data = {"rpm":[],"load_curr":[],"batt_output":[],"power_cap":[]}
with open('power1.lvm') as f:
reader = csv.reader(f)
#trying to append the data of column "RPM" to dictionary
rowcount = 0
for row in reader:
if rowcount == 0:
#trying to skip the first row
rowcount = rowcount + 1
else:
power_data['rpm'].append(row[0])
print(row)
json_report = {}
json_report['pwr_capacity_data'] = power_data
with open('LVMJSON', "w") as f1:
f1.write(json.dumps(json_report, sort_keys=False, indent=4, separators=(',', ': '),encoding="utf-8",ensure_ascii=False))
f1.close()
if __name__ == "__main__":
main()
The output json file that i am getting is this:(please ignore the print(row) statement in my code)
{
"pwr_capacity_data":
{
"load_curr": [],
"rpm": [
"1200,30,12.62,37.88",
"1600,88,18.62,55.88"
],
"batt_output": [],
"power_cap": []
}
}
The whole row is getting saved in the list,but I just want the values under the column RPM to be saved .Can someone help me out with what I may be doing wrong.Thanks in advance.I have attached an image of csv file to just in case it helps

You could use Python's defaultdict to make it a bit easier. Also a dictionary to map all your header values.
from collections import defaultdict
import csv
import json
power_data = defaultdict(list)
header_mappings = {
'RPM' : 'rpm',
'Load Current' : 'load_curr',
'Battery Output' : 'batt_output',
'Power Capacity' : 'power_cap'}
with open('power1.lvm', newline='') as f_input:
csv_input = csv.DictReader(f_input)
for row in csv_input:
for key, value in row.items():
power_data[header_mappings[key]].append(value)
with open('LVMJSON.json', 'w') as f_output:
json.dump({'power_capacity_data' : power_data}, f_output, indent=2)
Giving you an output JSON file looking like:
{
"power_capacity_data": {
"batt_output": [
"12",
"18"
],
"power_cap": [
"37",
"55"
],
"load_curr": [
"30",
"88"
],
"rpm": [
"1200",
"1600"
]
}
}

Related

Is there a way to rename empty header CSV file converting to JSON in Python without pandas?

I am trying to convert a CSV file to JSON but there is a header in my csv that is empty. Is there a way to name it when outputting it to JSON?
Example data
"" Calories Fat Sodium
Bread 100 10 23
I got this code from geeksforgeeks
import csv
import json
# Function to convert a CSV to JSON
# Takes the file paths as arguments
def make_json(csvFilePath, jsonFilePath):
# create a dictionary
data = {}
# Open a csv reader called DictReader
with open(csvFilePath, encoding='utf-8') as csvf:
csvReader = csv.DictReader(csvf)
# Convert each row into a dictionary
# and add it to data
for rows in csvReader:
# Assuming a column named 'No' to
# be the primary key
key = rows['']
data[key] = rows
# Open a json writer, and use the json.dumps()
# function to dump data
with open(jsonFilePath, 'w', encoding='utf-8') as jsonf:
jsonf.write(json.dumps(data, indent=4))
# Driver Code
# Decide the two file paths according to your
# computer system
csvFilePath = r'Names.csv'
jsonFilePath = r'Names.json'
# Call the make_json function
make_json(csvFilePath, jsonFilePath)
I did this and it gets the first row, but i'm not sure how to rename it when i output it to JSON.
It appears as "":"Bread" in the JSON file.
key = rows['']
Thanks in advance if anyone can help!
Edit: Expected output
{
"Food": "Bread",
"Calories": "45",
"Fat (g)": "0",
"Carb. (g)": "11",
"Fiber (g)": "0",
"Protein": "0",
"Sodium": "10"
}

Save a "pretty" JSON Object to disc with json.dump in Python

I try to save a "pretty" json object which I created from a pandas dataframe.
df = pd.read_csv("https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/5f23f993cd87c283ce766e7ac6b329ee7cc2e1d1/mtcars.csv")
import json
d = df.to_dict(orient='records')
j = json.dumps(d, indent=2)
print(j)
The printed output looks great and when I copy it to an editor, it seems to work.
[
{
"model": "Mazda RX4",
"mpg": 21.0,
"cyl": 6,
"disp": 160.0,
"hp": 110,
"drat": 3.9,
"wt": 2.62,
"qsec": 16.46,
"vs": 0,
"am": 1,
"gear": 4,
"carb": 4
}
]
However, when I save it to disc, I does not look like expected.
with open("beispiel.json", "w") as write_file:
json.dump(j, write_file)
Everything is in one line and is not formatted at all:
"[\n {\n \"model\": \"Mazda RX4\",\n \"mpg\": 21.0,\n \"cyl\": 6,\n \"disp\": 160.0,\n
What am I doing wrong here?
The reason is that j is a string, so when you do:
with open("beispiel.json", "w") as write_file:
json.dump(j, write_file)
you are writing the string to the file. Just do:
json.dump(d, write_file, indent=2)
Try this:
import json
import pandas as pd
df = pd.read_csv("https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/5f23f993cd87c283ce766e7ac6b329ee7cc2e1d1/mtcars.csv")
d = df.to_dict(orient='records')
# 1st form
with open("beispiel.json", "w") as write_file:
write_file.write(json.dumps(d, indent=2))
# or 2nd form
with open("beispiel.json", "w") as write_file:
json.dump(d, write_file, indent=2)

How to print number only from a .json file in python

I want to print only the number from "PresentValue". But only from "ObjectIdentifier" : 1
I need to be able to specify what "ObjectIdentifier" that is going to be printed.
Here is my json file:
import json
# Data to be written
data = {
"AnalogValues": [
{
"ObjectIdentifier": 1,
"PresentValue": 10.2
},
{
"ObjectIdentifier": 2,
"PresentValue": 20.3
}
]
}
# Serializing json
json_object = json.dumps(data, indent = 4)
# Writing to sample.json
with open("AnalogValues.json", "w") as outfile:
outfile.write(json_object)
This is what I have tried so far (returns the whole json file):
import json
# Opening JSON file
with open('AnalogValues.json', 'r') as openfile:
# Reading from json file
json_object = json.load(openfile)
print(json_object)
print(type(json_object))
You can use function like this:
def get_present_value(no):
for a in data['AnalogValues']:
if a['ObjectIdentifier'] == int(no):
return a['PresentValue']
return None
print(get_present_value(2))
Output:
20.3

How to write line by line request output

I am trying to write line by line the JSON output from my Python request. I already checked some similar issue on StackOverflow in the question: write to file line by line python, without success.
Here is the code:
myfile = open ("data.txt", "a")
for item in pretty_json["geonames"]:
print (item["geonameId"],item["name"])
myfile.write ("%s\n" % item["geonameId"] + "https://www.geonames.org/" + item["name"])
myfile.close()
Here the output from my pretty_json["geonames"]
{
"adminCode1": "FR",
"lng": "7.2612",
"geonameId": 2661847,
"toponymName": "Aeschlenberg",
"countryId": "2658434",
"fcl": "P",
"population": 0,
"countryCode": "CH",
"name": "Aeschlenberg",
"fclName": "city, village,...",
"adminCodes1": {
"ISO3166_2": "FR"
},
"countryName": "Switzerland",
"fcodeName": "populated place",
"adminName1": "Fribourg",
"lat": "46.78663",
"fcode": "PPL"
}
Then, as output saved on my data.txt, I'm having :
11048419
https://www.geonames.org/Aïre2661847
https://www.geonames.org/Aeschlenberg2661880
https://www.geonames.org/Aarberg6295535
The expected result should be something like:
Aïre , https://www.geonames.org/11048419
Aeschlenberg , https://www.geonames.org/2661847
Aarberg , https://www.geonames.org/2661880
Writing the output in CSV could be a solution?
Regards.
Using the csv module.
Ex:
import csv
with open("data.txt", "a") as myfile:
writer = csv.writer(myfile) #Create Writer Object
for item in pretty_json["geonames"]: #Iterate list
writer.writerow([item["name"], "https://www.geonames.org/{}".format(item["geonameId"])]) #Write row.
If I understand correctly, you want the same screen output to your file. That's easy. If you are on python 3 just add to your print function:
print (item["geonameId"],item["name"], file=myfile)
Just compose a proper printing format for the needed items:
...
for item in pretty_json["geonames"]:
print("{}, https://www.geonames.org/{}".format(item["name"], item["geonameId"]))
Sample output:
Aeschlenberg, https://www.geonames.org/2661847

Python: csv to json converter value to key pair

I had a Python beginners course last year. Now I am trying to get a csv to json converter. I have searched quite some time and adapted and changed some of the code I found, until the output looked similar to what I want. I am using Python 3.4.2.
#kvorobiev this is an excerpt of my CSV, but it will do for the case. The first time Converting will work. After the second time you will see that the order of the headings will change within the json file.
The csv file looks like this
Document;Item;Category
4;10;C
What I am getting in the output file as of now (after applying the changes from kvorobiev):
[
{
"Item": "10",
"Category": "C",
"Document": "4"
};
]
The json string I want to get in the output file should look like:
[
{
"Document": "4",
"Item": "10",
"Category": "C"
},
]
You will notice the headings are in the wrong order.
Here is the code:
import json
import csv
csvfile = open('file1.csv', 'r')
jsonfile = open('file1.csv'.replace('.csv','.json'), 'w')
jsonfile.write('[' + '\n' + ' ')
fieldnames = csvfile.readline().replace('\n','').split(';')
num_lines = sum(1 for line in open('file.csv')) -1
reader = csv.DictReader(csvfile, fieldnames)
i = 0
for row in reader:
i += 1
json.dump(row, jsonfile, indent=4,sort_keys=False)
if i < num_lines:
jsonfile.write(',')
jsonfile.write('\n')
jsonfile.write(' ' + ']')
print('Done')
Thanks for helping.
Replace line
reader = csv.DictReader(csvfile, fieldnames)
with
reader = csv.DictReader(csvfile, fieldnames, delimiter=';')
Also, you open file1.csv and later get lines number from file.csv
num_lines = sum(1 for line in open('file.csv')) -2
Your solution could be reduced to
import json
import csv
csvfile = open('file1.csv', 'r')
jsonfile = open('file1.csv'.replace('.csv','.json'), 'w')
jsonfile.write('{\n[\n')
fieldnames = csvfile.readline().replace('\n','').split(';')
reader = csv.DictReader(csvfile, fieldnames, delimiter=';')
for row in reader:
json.dump(row, jsonfile, indent=4)
jsonfile.write(';\n')
jsonfile.write(']\n}')
If you want to save order of columns from csv you could use
from collections import OrderedDict
...
for row in reader:
json.dump(OrderedDict([(f, row[f]) for f in fieldnames]), jsonfile, indent=4)
jsonfile.write(';\n')
jsonfile.write(']\n}')

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