Sort nested dict with Python

sort_nested_dict.py

#!coding: utf-8

complex_dict = { 
    "x": {"c1": 200, "c2": 100, },
    "z": {"c1": 100, "c2": 200, },
    "y": {           "c2": 300, "c1": 500},
}

print "# original"
print complex_dict

print "# only iterate"
for elem in complex_dict.iteritems():
    print elem

print "# only sorted (sort by key)"
for elem in sorted(complex_dict.iteritems()):
    print elem

print "# sort by value's value(c1)"
for elem in sorted(complex_dict.iteritems(), key=lambda val: val[1]["c1"]):
    print elem

print "# sort by value's value(c2)"
for elem in sorted(complex_dict.iteritems(), key=lambda val: val[1]["c2"]):
    print elem

z_result.txt

➜  /tmp  python sort_nested_dict.py
# original
{'y': {'c2': 300, 'c1': 500}, 'x': {'c2': 100, 'c1': 200}, 'z': {'c2': 200, 'c1': 100}}
# only iterate
('y', {'c2': 300, 'c1': 500})
('x', {'c2': 100, 'c1': 200})
('z', {'c2': 200, 'c1': 100})
# only sorted (sort by key)
('x', {'c2': 100, 'c1': 200})
('y', {'c2': 300, 'c1': 500})
('z', {'c2': 200, 'c1': 100})
# sort by value's value(c1)
('z', {'c2': 200, 'c1': 100})
('x', {'c2': 100, 'c1': 200})
('y', {'c2': 300, 'c1': 500})
# sort by value's value(c2)
('x', {'c2': 100, 'c1': 200})
('z', {'c2': 200, 'c1': 100})
('y', {'c2': 300, 'c1': 500})

val is tuple. (key, value)

so val[0] is the key of dict, and val[1] is the value of dict.