How to check if a column exists in Pandas
This will work: But for clarity, I’d probably write it as:
Python
Copy a list of list by value and not reference
Because python passes lists by reference This means that when you write “b=a” you’re saying that a and b are the same object, and that when you change b you change also a, and viceversa A way to copy a list by value: If the list contains objects and you want to copy them as … Read more
What does “hashable” mean in Pytho
From the Python glossary: An object is hashable if it has a hash value which never changes during its lifetime (it needs a __hash__() method), and can be compared to other objects (it needs an __eq__() or __cmp__() method). Hashable objects which compare equal must have the same hash value. Hashability makes an object usable as a dictionary key and a set … Read more
How can I check whether a numpy array is empty or not?
You can always take a look at the .size attribute. It is defined as an integer, and is zero (0) when there are no elements in the array:
super(type, obj): obj must be an instance or subtype of type
You should call super using the UrlManager class as first argument not the URL model. super cannot called be with an unrelated class/type: From the docs, super(type[, object-or-type]): Return a proxy object that delegates method calls to a parent or sibling class of type. So you cannot do: You should do: Or in Python 3:
Properly formatted multiplication table
Quick way (Probably too much horizontal space though): Better way: And using f-strings (Python3.6+)
What is the meaning of curly braces?
“Curly Braces” are used in Python to define a dictionary. A dictionary is a data structure that maps one value to another – kind of like how an English dictionary maps a word to its definition. Python: They are also used to format strings, instead of the old C style using %, like: They are … Read more
“Can’t convert ‘float’ object to str implicitly”
floats can’t be implicitly converted into strings. You need to do it explicitly. But it’s better to use format.
Error: OOM when allocating tensor with shape
i am facing issue with my inception model during the performance testing with Apache JMeter. Error: OOM when allocating tensor with shape[800,1280,3] and type float on /job:localhost/replica:0/task:0/device:GPU:0 by allocator GPU_0_bfc [[Node: Cast = CastDstT=DT_FLOAT, SrcT=DT_UINT8, _device=”/job:localhost/replica:0/task:0/device:GPU:0″]] Hint: If you want to see a list of allocated tensors when OOM happens, add report_tensor_allocations_upon_oom to RunOptions for … Read more
Subtract two columns in dataframe
Given the following dataframe: It comes down to a simple broadcasting operation: