Create JSON-files.md

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+JSON (JavaScript Object Notation) is a widely used format for storing and exchanging data. It's particularly popular in web applications due to its lightweight and easy-to-read structure. In Python, handling JSON files is straightforward thanks to the built-in `json` library.
+
+Here’s an explanation and examples to help you work with JSON files in Python.
+
+### 1. Loading JSON Data
+
+To load JSON data from a file, use the `json.load()` method. This method reads the JSON file and parses it into a Python dictionary.
+
+#### Example: Loading JSON from a File
+
+Suppose we have a file `data.json`:
+
+```json
+{
+  "name": "Alice",
+  "age": 30,
+  "city": "Lisbon",
+  "languages": ["English", "Portuguese", "Spanish"]
+}
+```
+
+Here’s how to read this file in Python:
+
+```python
+import json
+
+# Open and load JSON file
+with open('data.json', 'r') as file:
+    data = json.load(file)
+
+print(data)
+# Output: {'name': 'Alice', 'age': 30, 'city': 'Lisbon', 'languages': ['English', 'Portuguese', 'Spanish']}
+```
+
+### 2. Accessing JSON Data
+
+After loading JSON data, you can access the values just like with a Python dictionary.
+
+#### Example: Accessing JSON Data
+
+```python
+print(data['name'])        # Output: Alice
+print(data['languages'])   # Output: ['English', 'Portuguese', 'Spanish']
+```
+
+### 3. Writing JSON Data
+
+To write data to a JSON file, use the `json.dump()` method, which serializes a Python dictionary and writes it to a file.
+
+#### Example: Writing JSON to a File
+
+```python
+data_to_save = {
+    "name": "Bob",
+    "age": 25,
+    "city": "Porto",
+    "languages": ["English", "Portuguese"]
+}
+
+# Write data to JSON file
+with open('output.json', 'w') as file:
+    json.dump(data_to_save, file, indent=4)
+```
+
+The `indent` parameter is optional but helps format the JSON for readability.
+
+#### Resulting `output.json` File
+
+```json
+{
+    "name": "Bob",
+    "age": 25,
+    "city": "Porto",
+    "languages": [
+        "English",
+        "Portuguese"
+    ]
+}
+```
+
+### 4. Converting JSON Strings
+
+If the JSON data comes as a string (e.g., from an API), you can use `json.loads()` to convert it to a Python dictionary.
+
+#### Example: Loading JSON from a String
+
+```python
+json_string = '{"name": "Charlie", "age": 28, "city": "Coimbra"}'
+data = json.loads(json_string)
+
+print(data)
+# Output: {'name': 'Charlie', 'age': 28, 'city': 'Coimbra'}
+```
+
+### 5. Converting a Python Dictionary to JSON String
+
+To convert a Python dictionary back to a JSON-formatted string, use `json.dumps()`.
+
+#### Example: Converting Dictionary to JSON String
+
+```python
+data_dict = {
+    "name": "Diana",
+    "age": 22,
+    "city": "Faro"
+}
+
+json_string = json.dumps(data_dict, indent=4)
+print(json_string)
+```
+
+### 6. Practical Example: Merging JSON Data
+
+Imagine you have two JSON files and want to combine them.
+
+File `file1.json`:
+```json
+{
+  "name": "Alice",
+  "age": 30
+}
+```
+
+File `file2.json`:
+```json
+{
+  "city": "Lisbon",
+  "languages": ["English", "Portuguese"]
+}
+```
+
+#### Code to Merge JSON Files
+
+```python
+with open('file1.json', 'r') as file1, open('file2.json', 'r') as file2:
+    data1 = json.load(file1)
+    data2 = json.load(file2)
+
+# Merging the dictionaries
+merged_data = {**data1, **data2}
+
+with open('merged_output.json', 'w') as outfile:
+    json.dump(merged_data, outfile, indent=4)
+```
+
+#### Resulting `merged_output.json`:
+
+```json
+{
+    "name": "Alice",
+    "age": 30,
+    "city": "Lisbon",
+    "languages": [
+        "English",
+        "Portuguese"
+    ]
+}
+```
+
+### Summary of Key Functions
+
+- **`json.load(file)`**: Load JSON data from a file.
+- **`json.dump(data, file)`**: Write Python data to a JSON file.
+- **`json.loads(string)`**: Parse JSON from a string.
+- **`json.dumps(data)`**: Convert Python data to a JSON string.
+
+These methods make handling JSON data in Python efficient, whether you’re reading from files, writing to them, or manipulating JSON structures.