OTLibPy27

MQL4/Libraries/OTMql4/OTLibPy27.mq4

This will provide our logging functions that work with Python. See OTLibLog for just a skeleton logging. We introduce a global variable fDebugLevel which ranges from 0 to 5: "PANIC", "ERROR", "WARNING", "INFO", "DEBUG", "TRACE" If you set the variable to 1, you will only see errors; if you set it to 2 you will see warnings and errors... The Mt4 code can use vLog(iLevel, uMsg) to log accordingly. The Python code can use vLog(iLevel, sMsg) to log accordingly. Wrappers around the imported funtions for strings: they expect uchar[] arrays, not unicode strings.

void vPyExecuteUnicode (string uSource)

int iPyEvaluateUnicode (string uSource)

int iPyNewStringUnicode(string &uSource)

int iPyLookupDictUnicode(int p_dict, string uName) Below are some higher level abstractions, here you dont have to care about reference counting when using the functions, you will not be exposed to handles of python objects.

int iPyInit(string sStdOut) Initializes the Python environment. This should be called from your OnInit() function. It is safe to call it a second time; subsequent calls will just be ignored. It should return 0. A return value of -1 is a panic: remove the expert if it requires Python.

void vPyOutEmpty() empty the stdout file (where the redirected print output and errors go)

void vPyPrintAndClearLastError() You MUST do something to clear any error condition or the system will crash, as documented in the Python manual.

string ePySafeExec(string uSource) Evaluate a python expression has no return value and return any errors as a string, otherwise return "" In the caller you should have something like: {{{ if (StringCompare(uRetval, "") != 0) { Print("Error in Python execing: " + uSource + "\n" + res); <do something as a result of the failure> } }}}

string uPySafeEval(string uSource) Evaluate a python expression that will evaluate to a string and return its value In the caller you should have something like: {{{ if (StringFind(uRetval, "ERROR:", 0) == 0) { Print("Error in Python evaluating: " + uSource + "\n" + res); <do something as a result of the failure> } }}}

void vPanic(string uReason) A panic prints an error message and then aborts

int iPySafeExec(string uArg)

int iPyEvalInt(string uSource) Evaluate a python expression that will evaluate to an integer and return its value

double fPyEvalDouble(string uSource) Evaluate a python expression that will evaluate to a double and return its value

string uPyEvalUnicode(string uSource)

int iPyListAppendInt(string list_name, int &array[]) append the array of int to the python list given by its name. the list must already exist. The same could be achieved by putting vPyExecuteUnicode() calls with generated python code into a loop but this would invoke parser and compiler for every new list item, directly accessing the python objects like it is done here is far more effective.

int iPyListAppendDouble(string list_name, double &array[]) append the array of double to the python list given by its name. the list must already exist.

int iPyListAppendString(string list_name, string &array[]) Append the array of string to the python list given by its name. the list must already exist.

void vPyDeInit()

string uChartName(string uSymbol, int iPeriod, long iWindowId, int iExtra=0) We will need a unique identifier for each chart

Source code: MQL4/Libraries/OTMql4/OTLibPy27.mq4

This file is automatically generated from the source code: do not edit.

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Parent: CodeLibraries