how to extract data from a code using python

Question

I have some functions, as .txt files which are written using easy language and I need to extract data from those functions using python. as an example consider the following part.

code segment -

If MarketPosition = 0 and (EntriesToday(Date) < 1 or EndofSess) and
EntCondL 
then begin
    Buy("EnStop-L") NShares shares next bar at EntPrL stop;
end;

in here, I need to extract the parts

MarketPosition = 0
EntriesToday(Date) < 1
EndofSess
EntCondL

and identify =, < signs using python. thanks in advance.

you probably need a language parser or [lexer](https://en.wikipedia.org/wiki/Lexical_analysis) — gtatr, Sep 27 '18 at 13:24
Is it always between `If...then` or is that just an example? — cuzi, Sep 27 '18 at 19:17

score 1 · Accepted Answer · answered Sep 30 '18 at 19:19

Here is an example for finding and splitting the text between if and then The result is a list of the individual elements: variables, brackets and the comparison operators.

code = """
If MarketPosition = 0 and (EntriesToday(Date) < 1 or EndofSess) and
EntCondL 
then begin
    Buy("EnStop-L") NShares shares next bar at EntPrL stop;
end;
"""

import re
words = re.split("\s+|(\(|\)|<|>|=|;)", code)

is_if = False
results = []
current = None
for token in words:
    if not token:
        continue
    elif token.lower() == "if":
        is_if = True
        current = []
    elif token.lower() == "then":
        is_if = False
        results.append(current)
    elif is_if:
        if token.isdecimal(): # Detect numbers
            try:
                current.append(int(token))
            except ValueError:
                current.append(float(token))
        else: # otherwise just take the string
            current.append(token)



print(results)

The result:

['MarketPosition', '=', 0, 'and', '(', 'EntriesToday', '(', 'Date', ')', '<', 1, 'or', 'EndofSess', ')', 'and', 'EntCondL']

I think it's easier to go from here (I don't in which form you need the data, for example do the brackets matter?)

as you said brackets doesn't matter actually ... i was able to get the job done through your code fragment. thanks again — Bhashitha Hemantha, Oct 01 '18 at 04:05

score 1 · Answer 2 · answered Sep 30 '18 at 19:32

1

i think you are looking for prefix and postfix of some operators
i suggest you to find these list of operators and use it's location to get prefix and postfix

answered Sep 30 '18 at 19:32

Muhammad Yusuf

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how to extract data from a code using python

2 Answers2