Python cbook.safe_first_element方法代码示例

# 需要导入模块: from matplotlib import cbook [as 别名]
# 或者: from matplotlib.cbook import safe_first_element [as 别名]
def get_converter(self, x):
        """Get the converter interface instance for *x*, or None."""
        if hasattr(x, "values"):
            x = x.values  # Unpack pandas Series and DataFrames.
        if isinstance(x, np.ndarray):
            # In case x in a masked array, access the underlying data (only its
            # type matters).  If x is a regular ndarray, getdata() just returns
            # the array itself.
            x = np.ma.getdata(x).ravel()
            # If there are no elements in x, infer the units from its dtype
            if not x.size:
                return self.get_converter(np.array([0], dtype=x.dtype))
        try:  # Look up in the cache.
            return self[type(x)]
        except KeyError:
            try:  # If cache lookup fails, look up based on first element...
                first = cbook.safe_first_element(x)
            except (TypeError, StopIteration):
                pass
            else:
                # ... and avoid infinite recursion for pathological iterables
                # where indexing returns instances of the same iterable class.
                if type(first) is not type(x):
                    return self.get_converter(first)
        return None 

# 需要导入模块: from matplotlib import cbook [as 别名]
# 或者: from matplotlib.cbook import safe_first_element [as 别名]
def default_units(x, axis):
        """
        Return the tzinfo instance of *x* or of its first element, or None
        """
        if isinstance(x, np.ndarray):
            x = x.ravel()

        try:
            x = cbook.safe_first_element(x)
        except (TypeError, StopIteration):
            pass

        try:
            return x.tzinfo
        except AttributeError:
            pass
        return None 

# 需要导入模块: from matplotlib import cbook [as 别名]
# 或者: from matplotlib.cbook import safe_first_element [as 别名]
def test_flatiter():
    x = np.arange(5)
    it = x.flat
    assert 0 == next(it)
    assert 1 == next(it)
    ret = cbook.safe_first_element(it)
    assert ret == 0

    assert 0 == next(it)
    assert 1 == next(it) 

# 需要导入模块: from matplotlib import cbook [as 别名]
# 或者: from matplotlib.cbook import safe_first_element [as 别名]
def test_safe_first_element_pandas_series(pd):
    # delibrately create a pandas series with index not starting from 0
    s = pd.Series(range(5), index=range(10, 15))
    actual = cbook.safe_first_element(s)
    assert actual == 0 

# 需要导入模块: from matplotlib import cbook [as 别名]
# 或者: from matplotlib.cbook import safe_first_element [as 别名]
def get_converter(self, x):
        """
        Get the converter for data that has the same type as *x*. If no
        converters are registered for *x*, returns ``None``.
        """

        if not len(self):
            return None  # nothing registered
        # DISABLED idx = id(x)
        # DISABLED cached = self._cached.get(idx)
        # DISABLED if cached is not None: return cached

        converter = None
        classx = getattr(x, '__class__', None)

        if classx is not None:
            converter = self.get(classx)

        if converter is None and hasattr(x, "values"):
            # this unpacks pandas series or dataframes...
            x = x.values

        # If x is an array, look inside the array for data with units
        if isinstance(x, np.ndarray) and x.size:
            xravel = x.ravel()
            try:
                # pass the first value of x that is not masked back to
                # get_converter
                if not np.all(xravel.mask):
                    # some elements are not masked
                    converter = self.get_converter(
                        xravel[np.argmin(xravel.mask)])
                    return converter
            except AttributeError:
                # not a masked_array
                # Make sure we don't recurse forever -- it's possible for
                # ndarray subclasses to continue to return subclasses and
                # not ever return a non-subclass for a single element.
                next_item = xravel[0]
                if (not isinstance(next_item, np.ndarray) or
                        next_item.shape != x.shape):
                    converter = self.get_converter(next_item)
                return converter

        # If we haven't found a converter yet, try to get the first element
        if converter is None:
            try:
                thisx = safe_first_element(x)
            except (TypeError, StopIteration):
                pass
            else:
                if classx and classx != getattr(thisx, '__class__', None):
                    converter = self.get_converter(thisx)
                    return converter

        # DISABLED self._cached[idx] = converter
        return converter