Python 3.6嵌套字典动态更新：将特定格式文件转为嵌套字典

First, let's restate the input format we're working with (each line has a slash-separated key path and a value, split by a semicolon):

HP;1
MN;stringval
IS/VD1;32.00
IS/HD1;1.34
IS/E/ID;362.0000000
IS/OLVD;0.0000000
ISN/I/HFD;3283.8999023
D1/I/MF;7.3059464
D1/I/P;32.0388412
D1/E/E;2778.4829102
D1/S1/SB/I/P;32.0388412
EN;5145

Step-by-Step Implementation #

We'll create a helper function to dynamically update the nested dictionary, plus logic to process each line and handle value type conversion (so numbers are stored as integers/floats instead of strings).

Code Implementation #

def update_nested_dict(outer_dict, key_path, value):
    # Split the slash-separated key path into individual keys
    keys = key_path.split('/')
    # Traverse to the parent level of the final key
    current_dict = outer_dict
    for key in keys[:-1]:
        # Create the nested dict if it doesn't exist yet
        current_dict = current_dict.setdefault(key, {})
    
    # Convert value to appropriate type (int > float > string)
    try:
        final_value = int(value)
    except ValueError:
        try:
            final_value = float(value)
        except ValueError:
            final_value = value.strip()
    
    # Set the final value at the deepest key level
    current_dict[keys[-1]] = final_value

# Process input lines (replace with file reading logic if needed)
input_lines = [
    "HP;1",
    "MN;stringval",
    "IS/VD1;32.00",
    "IS/HD1;1.34",
    "IS/E/ID;362.0000000",
    "IS/OLVD;0.0000000",
    "ISN/I/HFD;3283.8999023",
    "D1/I/MF;7.3059464",
    "D1/I/P;32.0388412",
    "D1/E/E;2778.4829102",
    "D1/S1/SB/I/P;32.0388412",
    "EN;5145"
]

# Initialize empty nested dictionary
nested_dict = {}

# Process each line to populate the dictionary
for line in input_lines:
    if ';' not in line:
        continue  # Skip lines without valid key-value split
    # Split only once to handle values that might contain semicolons
    key_part, value_part = line.split(';', 1)
    update_nested_dict(nested_dict, key_part.strip(), value_part.strip())

# Print the result with pretty formatting
import pprint
pprint.pprint(nested_dict)

How It Works #

• update_nested_dict Function:

  • Splits the key path (like IS/E/ID) into a list of keys: ["IS", "E", "ID"]
  • Uses setdefault to safely traverse or create nested dictionaries at each level (no need for messy conditional checks)
  • Converts the value to the most appropriate type: first tries integer, then float, falls back to string if neither works

• Main Processing Loop:

  • Iterates over each input line, skipping any invalid lines that lack a semicolon
  • Splits each line into key path and value (only splits once, so values with semicolons are preserved)
  • Calls the helper function to build out the nested dictionary incrementally

Sample Output #

When you run the code, you'll get this properly structured nested dictionary:

{'D1': {'E': {'E': 2778.4829102},
        'I': {'MF': 7.3059464, 'P': 32.0388412},
        'S1': {'SB': {'I': {'P': 32.0388412}}}},
 'EN': 5145,
 'HP': 1,
 'IS': {'E': {'ID': 362.0},
        'HD1': 1.34,
        'OLVD': 0.0,
        'VD1': 32.0},
 'ISN': {'I': {'HFD': 3283.8999023}},
 'MN': 'stringval'}

Reading from a File #

If your data is stored in a file, replace the input_lines list with this file reading code:

with open('your_file.txt', 'r') as file:
    input_lines = file.read().splitlines()

内容的提问来源于stack exchange，提问作者Giuseppe Salerno