Pandas Merging 101
Merging basics – basic types of joins (read this first)
concatenation
How do I concatenate items in a list to a single string?
How do I concatenate a list of strings into a single string?
Import multiple csv files into pandas and concatenate into one DataFrame
I would like to read several csv files from a directory into pandas and concatenate them into one big DataFrame. I have not been able to figure it out though. Here is what I have so far:
How can I concatenate str and int objects?
If I try to do the following:
Why does concatenation of DataFrames get exponentially slower?
I have a function which processes a DataFrame, largely to process data into buckets create a binary matrix of features in a particular column using pd.get_dummies(df[col]).
How do I concatenate text files in Python?
I have a list of 20 file names, like ['file1.txt', 'file2.txt', ...]. I want to write a Python script to concatenate these files into a new file. I could open each file by f = open(...), read line by line by calling f.readline(), and write each line into that new file. It doesn’t seem very “elegant” to me, especially the part where I have to read/write line by line.
Which is the preferred way to concatenate a string in Python?
Since Python’s string can’t be changed, I was wondering how to concatenate a string more efficiently?
Python strings and integer concatenation
TypeError: unsupported operand type(s) for +: ‘int’ and ‘str’
String concatenation without ‘+’ operator
I was playing with python and I realized we don’t need to use ‘+’ operator to concatenate static strings. But it fails if I assign it to a variable.
Concatenating two one-dimensional NumPy arrays
I have two simple one-dimensional arrays in NumPy. I should be able to concatenate them using numpy.concatenate. But I get this error for the code below: