symbol select HOW

symbol_select — How it works¶

📌 Overview¶

This example shows how to use the low-level asynchronous method symbol_select() to manage Market Watch content — add and remove symbols.

The example implements a practical task: cleaning Market Watch of all symbols except a predefined list.

Method Signature¶

async def symbol_select(
    symbol: str,
    select: bool,
    deadline: Optional[datetime] = None,
    cancellation_event: Optional[asyncio.Event] = None,
):

Key points:

The method is asynchronous and called with await
symbol — trading symbol name
select=True adds the symbol to Market Watch
select=False removes the symbol from Market Watch
The method returns the operation result

🧩 Code Example — Market Watch Cleanup¶

async def cleanup_market_watch(account: MT5Account, keep_symbols: list[str]):
    total_data = await account.symbols_total(selected_only=True)
    total = total_data.total

    removed = []
    for i in range(total):
        name_data = await account.symbol_name(index=i, selected=True)
        symbol = name_data.name

        if symbol not in keep_symbols:
            data = await account.symbol_select(symbol=symbol, select=False)
            if data.success:
                removed.append(symbol)
                print(f"Removed: {symbol}")

    print(f"Removed {len(removed)} symbols from Market Watch")
    return removed

This example demonstrates practical use of symbol_select() for managing the displayed symbols list.

🟢 Detailed Explanation¶

1️⃣ Getting Selected Symbols Count¶

total_data = await account.symbols_total(selected_only=True)
total = total_data.total

At this step:

the number of symbols in Market Watch is requested
this value is used as the iteration boundary

2️⃣ Iterating Through Symbols by Index¶

for i in range(total):

The code sequentially iterates through all symbols currently added to Market Watch.

3️⃣ Getting Symbol Name¶

name_data = await account.symbol_name(index=i, selected=True)
symbol = name_data.name

At this step:

the symbol name is obtained by index
the name is used to decide on removal

4️⃣ Removing Symbol from Market Watch¶

data = await account.symbol_select(symbol=symbol, select=False)

If the symbol is not in the keep_symbols list:

symbol_select() is called with select=False
a command is sent to the terminal to remove the symbol from Market Watch

5️⃣ Checking Operation Result¶

if data.success:

The method returns an object with a success flag:

True — operation completed successfully
False — operation was not completed

User code decides how to interpret the result.

The Role of Low-Level Method¶

Clear boundary of responsibility:

symbol_select():

adds or removes a symbol from Market Watch
performs one specific operation
returns the operation result

cleanup_market_watch():

determines which symbols to keep
manages list iteration
decides on removal
aggregates the result

Summary¶

This example illustrates the state management pattern through low-level API:

get current state → make decision → change state → check result

The symbol_select() method performs an atomic operation of adding or removing a symbol, while all Market Watch management logic is implemented on the user code side.