I am currently in the process of using python to transmit a python dictionary from one raspberry pi to another over a 433Mhz link, using virtual wire (vw.py) to send data.
The issue with vw.py is that data being sent is in string format.
I am successfully receiving the data on PI_no2, and now I am trying to reformat the data so it can be placed back in a dictionary.
I have created a small snippet to test with, and created a temporary string in the same format it is received as from vw.py
So far I have successfully split the string at the colon, and I am now trying to get rid of the double quotes, without much success.
my_status = {}
#temp is in the format the data is recieved
temp = "'mycode':['1','2','firstname','Lastname']"
key,value = temp.split(':')
print key
print value
key = key.replace("'",'')
value = value.replace("'",'')
my_status.update({key:value})
print my_status
Gives the result
'mycode'
['1','2','firstname','Lastname']
{'mycode': '[1,2,firstname,Lastname]'}
I require the value to be in the format
['1','2','firstname','Lastname']
but the strip gets rid of all the single speech marks.
You can use ast.literal_eval
import ast
temp = "'mycode':['1','2','firstname','Lastname']"
key,value = map(ast.literal_eval, temp.split(':'))
status = {key: value}
Will output
{'mycode': ['1', '2', 'firstname', 'Lastname']}
This shouldn't be hard to solve. What you need to do is strip away the [ ] in your list string, then split by ,. Once you've done this, iterate over the elements are add them to a list. Your code should look like this:
string = "[1,2,firstname,lastname]"
string = string.strip("[")
string = string.strip("]")
values = string.split(",")
final_list = []
for val in values:
final_list.append(val)
print final_list
This will return:
> ['1','2','firstname','lastname']
Then take this list and insert it into your dictionary:
d = {}
d['mycode'] = final_list
The advantage of this method is that you can handle each value independently. If you need to convert 1 and 2 to int then you'll be able to do that while leaving the other two as str.
Alternatively to cricket_007's suggestion of using a syntax tree parser - you're format is very similar to the standard yaml format. This is a pretty lightweight and intutive framework so I'll suggest it
a = "'mycode':['1','2','firstname','Lastname']"
print yaml.load(a.replace(":",": "))
# prints the dictionary {'mycode': ['1', '2', 'firstname', 'Lastname']}
The only thing that's different between your format and yaml is the colon needs a space
It also will distinguish between primitive data types for you, if that's important. Drop the quotes around 1 and 2 and it determines that they're numerical.
Tadhg McDonald-Jensen suggested pickling in the comments. This will allow you to store more complicated objects, though you may lose the human-readable format you've been experimenting with
Related
I’m dealing with some serialized data fetched from an SQL Server database and that looks like this :
('|AFoo|BBaar|C61|DFoo Baar|E200060|F200523|G200240|', )
Any idea which format is this ? And is there any Python package that can deserilize this ?
What you show is a tuple that contains one value - a string. You can use string.split to construct a list of the string's component parts - i.e., AFoo, BBaar etc
t = ('|AFoo|BBaar|C61|DFoo Baar|E200060|F200523|G200240|', )
for e in t:
values = [v for v in e.split('|') if v]
print(values)
Output:
['AFoo', 'BBaar', 'C61', 'DFoo Baar', 'E200060', 'F200523', 'G200240']
Note:
The for loop is used as a generic approach that allows for multiple strings in the tuple. For the data fragment shown in the question, this isn't actually necessary
I parsed a extremely LONG dictionary for the the fields 'zones' to a variable called scanner_data. In the next paragraph I'm showing the type of scanner_data. The next line after that is the contents of scanner_data.
Variable: scanner_data. The type is : <class 'list'>
[{'id': '3', 'name': 'rcomultitfw', ALL THE REST OF THE STRING IS WORTHLESS TO ME. IT WILL GO ON FOR another 700 letters!
I want to parse the name field for the results of rcomultitfw. I've tried .split(). I've tried converting the list thats really a string to a dictionary so I could parse it again, however it crashes or my python skills are not up to par. If you print(scanner_data[1]) it states its out of range so its the only result of this list.
Just for your information this data was taken from tenables with PyTenables.sc, not sure if that will help or not. My end goal is to parse scan zone data from information from individual tenable scanners.
Please Please help. I was enjoying Python programming up until this point, now I'm pulling out my hair and having headaches. Thanks!
If you can post the code and the console details it would be alot better. However, from what's shown, the data returned is of type list and it contains only one index, so functions like ".split()" won't work since they are only meant for variable of type string. What you might be missing is to first get the dictionary wrapped inside the array then try to access this dictionary using the keys. Here is an example:
scanner_data = [{'id': '3', 'name': 'rcomultitfw', 'extras':'ALL THE REST OF THE STRING I'}]
print(scanner_data[0]['name'])
However, since your question is not so clear I'll try to give an answer for other two possible scenarios:
Scenario A, having a dictionary that's wrapped in a string inside the array:
import ast
scanner_data = ["{'id': '3', 'name': 'rcomultitfw', 'extras':'ALL THE REST OF THE STRING I'}"]
dict_data = scanner_data[0]
parsed_dict = ast.literal_eval(dict_data)
print(parsed_dict['name'])
Scenario B, having a faulty dictionary that will ruin the parser:
import ast
scanner_data = ["{'id': '3', 'name': 'rcomultitfw', 'ALL THE REST OF THE STRING I'}"]
dict_data = scanner_data[0]
adjusted_string = dict_data.split(',')
adjusted_string = adjusted_string[0] + "," + adjusted_string[1] + '}'
parsed_dict = ast.literal_eval(adjusted_string)
print(parsed_dict['name'])
This is not the best way to adjust faulty dictionaries but this can work for your own use case and you can but this logic in a loop if you have multiple dictionaries in the scanner_data list
I have data that look like this:
data = 'somekey:value4thekey&second-key:valu3-can.be?anything&third_k3y:it%can have spaces;too'
In a nice human-readable way it would look like this:
somekey : value4thekey
second-key : valu3-can.be?anything
third_k3y : it%can have spaces;too
How should I parse the data so when I do data['somekey'] I would get >>> value4thekey?
Note: The & is connecting all of the different items
How am I currently tackling with it
Currently, I use this ugly solution:
all = data.split('&')
for i in all:
if i.startswith('somekey'):
print i
This solution is very bad due to multiple obvious limitations. It would be much better if I can somehow parse it into a python tree object.
I'd split the string by & to get a list of key-value strings, and then split each such string by : to get key-value pairs. Using dict and list comprehensions actually makes this quite elegant:
result = {k:v for k, v in (part.split(':') for part in data.split('&'))}
You can parse your data directly to a dictionary - split on the item separator & then split again on the key,value separator ::
table = {
key: value for key, value in
(item.split(':') for item in data.split('&'))
}
This allows you direct access to elements, e.g. as table['somekey'].
If you don't have objects within a value, you can parse it to a dictionary
structure = {}
for ele in data.split('&'):
ele_split = ele.split(':')
structure[ele_split[0]] = ele_split[1]
You can now use structure to get the values:
print structure["somekey"]
#returns "value4thekey"
Since the keys have a common format of being in the form of "key":"value".
You can use it as a parameter to split on.
for i in x.split("&"):
print(i.split(":"))
This would generate an array of even items where every even index is the key and odd index being the value. Iterate through the array and load it into a dictionary. You should be good!
I'd format data to YAML and parse the YAML
import re
import yaml
data = 'somekey:value4thekey&second-key:valu3-can.be?anything&third_k3y:it%can have spaces;too'
yaml_data = re.sub('[:]', ': ', re.sub('[&]', '\n', data ))
y = yaml.load(yaml_data)
for k in y:
print "%s : %s" % (k,y[k])
Here's the output:
third_k3y : it%can have spaces;too
somekey : value4thekey
second-key : valu3-can.be?anything
I'm trying to process a log from Symphony using Pandas, but have some trouble with a malformed JSON which I can't parse.
An example of the log :
'{id:46025,
work_assignment:43313=>43313,
declaration:<p><strong>Bijkomende interventie.</strong></p>\r\n\r\n<p>H </p>\r\n\r\n<p><strong><em>Vaststellingen.</em></strong></p>\r\n\r\n<p><strong><em>CV. </em></strong>De.</p>=><p><strong>Bijkomende interventie.</strong></p>\r\n\r\n<p>He </p>\r\n\r\n<p><strong><em>Vaststellingen.</em></strong></p>\r\n\r\n<p><strong><em>CV. </em></strong>De.</p>,conclusions:<p>H </p>=><p>H </p>}'
What is the best way to process this?
For each part (id/work_assignment/declaration/etc) I would like to retrieve the old and new value (which are separated by "=>").
Use the following code:
def clean(my_log):
my_log.replace("{", "").replace("}", "") # Removes the unneeded { }
my_items = list(my_log.split(",")) # Split at the comma to get the pairs
my_dict = {}
for i in my_items:
key, value = i.split(":") # Split at the colon to separate the key and value
my_dict[key] = value # Add to the dictionary
return my_dict
Function returns a Python dictionary, which can then be converted to JSON using a serializer if needed, or directly used.
Hope I helped :D
Is there a simple way to create a dictionary from a list of formatted tuples. e.g. if I do something like:
d={"responseStatus":"SUCCESS","sessionId":"01234","userId":2000004904}
This creates a dictionary called d. However, if I want to create a dictionary from a string which contains the same string, I can't do that
res=<some command that returns {"responseStatus":"SUCCESS","sessionId":"01234","userId":2000004904}>
print res
# returns {"responseStatus":"SUCCESS","sessionId":"01234","userId":2000004904}
d=dict(res)
This throws an error that says:
ValueError: dictionary update sequence element #0 has length 1; 2 is required
I strongly strongly suspect that you have json on your hands.
import json
d = json.loads('{"responseStatus":"SUCCESS","sessionId":"01234","userId":2000004904}')
would give you what you want.
Use dict(zip(tuples))
>>> u = ("foo", "bar")
>>> v = ("blah", "zoop")
>>> d = dict(zip(u, v))
>>> d
{'foo': 'blah', 'bar': 'zoop'}
Note, if you have an odd number of tuples this will not work.
Based on what you gave is, res is
# returns {"responseStatus":"SUCCESS","sessionId":"01234","userId":2000004904}
So the plan is to grab the string starting at the curly brace to the end and use json to decode it:
import json
# Discard the text before the curly brace
res = res[res.index('{'):]
# Turn that text into a dictionary
d = json.loads(res)
All you need to do in your particular case is
d = eval(res)
And please keep security in mind when using eval, especially if you're mixing it with ajax/json.
UPDATE
Since others pointed out you might be getting this data over the web and it isn't just a "how to make this work" question, use this:
import json
json.loads(res)