How to Pretty print Python dictionary from command line?

You can pretty print a Python dictionary using multiple approaches. The pprint module provides capability to "pretty-print" arbitrary Python data structures in a readable format, while the json module offers another elegant solution with customizable indentation.

Using pprint Module

The pprint module is specifically designed for pretty-printing Python data structures ?

import pprint

a = {
    'bar': 22,
    'foo': 45,
    'nested': {'key1': 'value1', 'key2': 'value2'}
}

pprint.pprint(a, width=30)

{'bar': 22,
 'foo': 45,
 'nested': {'key1': 'value1',
            'key2': 'value2'}}

Using json Module

The json module provides cleaner formatting with customizable indentation ?

import json

a = {
    'bar': 22,
    'foo': 45,
    'nested': {'key1': 'value1', 'key2': 'value2'}
}

print(json.dumps(a, indent=4))

{
    "bar": 22,
    "foo": 45,
    "nested": {
        "key1": "value1",
        "key2": "value2"
    }
}

Command Line Usage

You can pretty print dictionaries directly from the command line using Python's -c flag ?

# Using pprint
python -c "import pprint; d={'a':1,'b':2}; pprint.pprint(d)"

# Using json
python -c "import json; d={'a':1,'b':2}; print(json.dumps(d, indent=2))"

Comparison

Conclusion

Use json.dumps() with indent parameter for cleanest output. Use pprint when working with complex Python objects that aren't JSON-serializable.