How to read multiple dictionaries from a file in python?

Question

I am relatively new to python. I am trying to read an ascii file with several dictionaries in it. The file has the following format.

{Key1: value1 key2: value2 ... } {Key1: value1 key2: value2 ... } { ... 

Each dictionary in a file is a nested dictionary. I am trying to read it as a list of dictionaries. is there an easy way to do this? I tried the following code but it does not work

 data = json.load(open('doc.txt')) 

Answer 1

Since the data in your input file is actually not in JSON or Python, you will need to parse it yourself. You really haven't indicated which valid keys and values ​​are in the dictionary, so the following only allows them to be alphanumeric character strings.

So, the given input file with the following contents is named doc.txt :

 {key1: value1 key2: value2 key3: value3 } {key4: value4 key5: value5 } 

The following reads and converts it into a list of Python dictionaries, consisting of alphanumeric keys and values:

 from pprint import pprint import re dictpat = r'\{((?:\s*\w+\s*:\s*\w+\s*)+)\}' # note non-capturing (?:) inner group itempat = r'(\s*(\w+)\s*:\s*(\w+)\s*)' # which is captured in this expr with open('doc.txt') as f: lod = [{group[1]:group[2] for group in re.findall(itempat, items)} for items in re.findall(dictpat, f.read())] pprint(lod) 

Conclusion:

 [{'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}, {'key4': 'value4', 'key5': 'value5'}] 

Answer 2

You will need to put it on a large list to make it work. i.e.

 [ {key1: val1, key2: val2, key3: val3, ...keyN: valN} , {key1: val1, key2: val2, key3: val3, ...keyN: valN} , {key1: val1, key2: val2, key3: val3, ...keyN: valN} . . . ] 

If you cannot change the format of the data file, I'm afraid you will have to turn your own function to interpret the data.

Answer 3

If the internal elements are valid JSON, the following may work. I dug up the source of the simplejson library and modified it according to your use case. SSCCE below.

 import re import simplejson FLAGS = re.VERBOSE | re.MULTILINE | re.DOTALL WHITESPACE = re.compile(r'[ \t\n\r]*', FLAGS) def grabJSON(s): """Takes the largest bite of JSON from the string. Returns (object_parsed, remaining_string) """ decoder = simplejson.JSONDecoder() obj, end = decoder.raw_decode(s) end = WHITESPACE.match(s, end).end() return obj, s[end:] def main(): with open("out.txt") as f: s = f.read() while True: obj, remaining = grabJSON(s) print ">", obj s = remaining if not remaining.strip(): break 

.. which with some similar JSON in out.txt outputs something like:

 > {'hello': ['world', 'hell', {'test': 'haha'}]} > {'hello': ['world', 'hell', {'test': 'haha'}]} > {'hello': ['world', 'hell', {'test': 'haha'}]} 

Answer 4

 import re fl = open('doc.txt', 'rb') result = map( lambda part: dict( re.match( r'^\s*(.*?)\s*:\s*(.*?)\s*$', # splits with ':' ignoring space symbols line ).groups() for line in part.strip().split('\n') # splits with '\n', new line is a new key-value ), re.findall( r'\{(.*?)\}', # inside of { ... } fl.read(), flags=re.DOTALL # considering '\n'-symbols ) ) fl.close()