code: def signed_series(series: Series, initial: int = None) -> Series:
      """Returns a Signed Series with or without an initial value
  
      Default Example:
      series = Series([3, 2, 2, 1, 1, 5, 6, 6, 7, 5])
      and returns:
      sign = Series([NaN, -1.0, 0.0, -1.0, 0.0, 1.0, 1.0, 0.0, 1.0, -1.0])
      """
      series = verify_series(series)
      sign = series.diff(1)
      sign[sign > 0] = 1
      sign[sign < 0] = -1
      sign.iloc[0] = initial
      return sign
  
file_path: pandas-ta/pandas_ta/utils/_core.py
imports: import re
  from pathlib import Path
  from sys import float_info
  from numpy import argmax, argmin
  from pandas import DataFrame, Series
  from pandas.api.types import is_datetime64_any_dtype
  from pandas_ta import Imports
label_desc: Use image node_id 10 for calling a global function with example usage: signed_series(series, initial) and returns: sign