NaN: not a number , INF:无穷大,-inf +inf , float('nan') float('+inf') float('-inf') int(), long() 都是向下转型,对应实数int long float还可以用以下方式取舍: bool布尔:用于if/while后做条件判断 True:非False即为True False: None, False, 数字类型0,
'max', 'maximum', 'maximum_sctype', 'may_share_memory', 'mean', 'median', 'memmap', 'meshgrid', 'mgrid', 'min', 'min_scalar_type', 'minimum', 'mintypecode', 'mirr', 'mod', 'modf', 'moveaxis', 'msort', 'multiply', 'nan', 'nan_to_num', 'nanargmax', 'nanargmin', ...
downcast:A dict of item->dtype of what to downcast if possible, or the string ‘infer’ which will try to downcast to an appropriate equal type (e.g. float64 to int64 if possible). 模拟数据 再模拟一份数据: df2 = pd.DataFrame([[np.nan, 2, np.nan, 0], [3, 4, np.nan, 1],...
def as_integer_ratio(self): """ 获取改值的最简比 """ """ float.as_integer_ratio() -> (int, int) Return a pair of integers, whose ratio is exactly equal to the original float and with a positive denominator. Raise OverflowError on infinities and a ValueError on NaNs. >>> (10.0)...
>>> a = "python" >>> b = "javascript" >>> assert a == b Traceback (most recent call last): File "<stdin>", line 1, in <module> AssertionError >>> assert (a == b, "Values are not equal") <stdin>:1: SyntaxWarning: assertion is always true, perhaps remove parentheses? >...
equal等于。not_equal不等于。logical_and逻辑与(&)。logical_or逻辑或(|)。logical_xor逻辑异或(^)。基本数组统计方法 名称说明sum对数组中全部或者是某个轴向的所有元素进行求和。零长度的数组的sum值为0。mean算术平均值。零长度的数组的mean值为NaN。std标准差。 自由度可调整(默认为n)。var方差。 自由度可...
# '>=' not supported between instances of 'list' and 'str'.所以不能使用上边的方法'''在Python中,字符串类型的数据是可以比较大小的,这种比较是基于字典序。对于格式一致的时间字符串,如"HH:MM:SS"或"YYYY-MM-DD HH:MM:SS",它们的字典序比较恰好也符合时间的顺序,因此这些字符串可以直接进行比较,以确...
当对象不相等时,这会产生“FutureWarning”:print assert_frame_equal(X, df) 输出None和警告 /usr/local/lib/python2.7/site-packages/numpy/core/numeric.py:2367: FutureWarning: numpy equal will not check object identity in the future. The comparison did not return the same result as suggested by th...
pandas will attempt to infer the `dtype`from the data.Note that when `data` is a NumPy array, ``data.dtype`` is*not* used for inferring the array type. This is becauseNumPy cannot represent all the types of data that can beheld in extension arrays.Currently, pandas will infer an exte...
This change arguably makes the behavior more correct, but changes it if an attribute compares equal by identity but not value, like float('nan'). #1310 Deprecations The repr_ns argument to attr.s is now deprecated. It was a workaround for nested classes in Python 2 and is pointless in ...