[Python] I do not understand how json.dump() in Python works in my specific case

I understood that json.dump() means that you will dump all the variable in json format into your json file.

I ran it perfectly in the first file:

import json

def write_json(new_data, file_name="data/emp_details.json"):
with open(file_name, 'r+') as f:
file_data = json.load(f)
file_data["emp_details"].append(new_data)
print(file_data)
f.seek(0)
json.dump(file_data, f, indent=2)

new_data = {"emp_name": "Nikhil",
"email": "nikhil@geekforgeeks.org",
"job_profile": "Full Time"}

write_json(new_data)


Here is the file before running:

{
"emp_details": [
{
"emp_name": "Shubham",
"email": "ksingh.shubh@gmail.com",
"job_profile": "intern"
},
{
"emp_name": "Gaurav",
"email": "gaurav.singh@gmail.com",
"job_profile": "developer"
}
}


Here is it after running:

{
"emp_details": [
{
"emp_name": "Shubham",
"email": "ksingh.shubh@gmail.com",
"job_profile": "intern"
},
{
"emp_name": "Gaurav",
"email": "gaurav.singh@gmail.com",
"job_profile": "developer"
},
{
"emp_name": "Nikhil",
"email": "nikhil@geekforgeeks.org",
"job_profile": "Full Time"
}
}


It worked perfectly as my intention.

But when I moved to the second file, I applied the same steps, but it did not work and confused me a lot.

with open("data/encouraging_message.json", "r+") as f:
f.seek(0)
data = f.read()
# print(data)
if data == "":
file_structure = {"encouragements": [encouraging_message]}
# print(file_structure)
json.dump(file_structure, f, indent=2)
else:
f.seek(0)
data = json.load(f)
# print(data)
print(data["encouragements"])
data["encouragements"].append(encouraging_message)
print(data["encouragements"])
print(data)
f.seek(0)
json.dump(data, f, indent=2)


Here is the encouraging_message.json file:

{
"encouragements": [
"You will be fine!",
"You will be fine!"
]
}


I want the result to be like this:

{
"encouragements": [
"You will be fine!",
"You will be fine!",
"You will be fine!"
]
}


But instead, it worked like this:

{
"encouragements": [
"You will be fine!",
"You will be fine!"
]
}"You will be fine!"
]
}


I tried to look around and read some documentations, but I cannot find the results.

Can anyone explain for me that why it worked like this, and how to fix it ?

Thanks in advance.

Continue reading...