name = 'varname' In : long Out : varname some_variable unit_id time a 1 0 2 1 b 1 2 2 3 c 1 4 2 5 d 1 6 2 7 In : wide = long. In : import pandas as pd In : import numpy as np In : long = pd. Keeps observations that are in both DataFrames. Keeps all observations in the "right" DataFrame. Keeps all observations in the "left" DataFrame. While how='inner' is the default for pd.merge. Of the merge to keep using the keyword argument how, e.g.,ĭf_joint = df1.join(df2, how='left') is the default for join
Pandas will figure that out based on whether the variables Merging with Pandas DataFrames does not require you to specify "many-to-one" or Beware that pd.merge will not keep the index of either DataFrame.
#Outreg stata 13 full#
If you want a full constant column on your DataFrame, you can do df = 7 or whatever the constant is. NOTE: For theseĮgen commands, newvar is a full (constant) column in Stata, while it is a scalar in Python. Manipulate df.columns like a list: df.columns = ['a', The rows of df that don't meet the condition will be missingĭf = df.rename(columns=). Shift().fillna(0) even though the end result is the same. shift(fillna=0) is much, much slower than Issue with with larger data sets (usually several gigabytes). In IPython to easily test which one is faster.
Sometimes, it doesn't matter which way you do it. This also means that sometimes there is more than one way to do things. It's like learningĪn alphabet with 26 letters and composing millions of words instead of learning Means that there are fewer base commands to learn in pandas. May annoying to type a few more characters, this is actually a good thing! It One-liner (for example, see Stata's drop varstem* below). Sometimes Python/pandas will require composed commands where Stata uses a In this way, you can create (i.e., "compose") new commands.
This command doesn't have it's ownĭedicated if command. So let's say the second command you know is df.describe() which is theĮquivalent of Stata's summary. Now know the general if syntax for every other pandas That can be acted upon independently of df itself. in Stata, except df is itself a DataFrame First,ĭf, which returns the rows of DataFrame df for This is a little more difficult in Stata where each line of codeįor example, let's say you know two commands in Python/pandas. "composability." That is, you can combine base-level commands to "create" whole One concept that will push your Python skills forward quickly is Because of this, in Python represents a list Looking for a variable-a list, a number, a string-that's been defined If you were to write df without quotes, Python would go That in many cases, will be simple text in Stata (e.g.,Īvg_income) while in Python it will be a string ( 'avg_income'). show where user-specified values go in each language. The Stata-to-Python translations below are written assuming that you have a Variable just like in Stata, except that when you reference a column, you also You can think of each column in a DataFrame as a That a DataFrame is itself a variable and you can work with any number ofĭataFrames at one time. Where each column and each row has a name. The Pandas package implements a kind of variable called aĭataFrame that acts a lot like the single dataset in Stata. Variables can be anything, a single number, a matrix, a list, a Python is a general purpose programming language where a "variable" is not aĬolumn of data. The dataset is a matrix where eachĬolumn is a "variable" with a unique name and each row has a number (the In Stata, you have one dataset in memory. Coding in Python is a little different than coding in Stata.