I want to search for ‘row3’ in the index of the DataFrame below, which should be 2 for a zero-based array. Is there a function which return the row number of ‘row3’? Thanks in advance for any help. Answer You could use Index.get_loc (docs): But this is a somewhat unusual access pattern…
Tag: pandas
Python Pandas Setting Dataframe index and Column names from an array
Lets say I have data loaded from an spreadsheet: and I have a the names in another dataframe for the rows and the columns for example Is there a way I can set the values in colnames[‘Names’].value as the index for df? and is there a way to do this for column names? Answer How about df.index = coln…
Pandas dataframe.dot division method
I am trying to divide two series of different length to return the matrix product dataframe of them. I can multiply them using the dot method (from this answer): I’ve tried the div method, but this just fills the dataframe with NaNs: Likewise the standard division operator also returns the same result: …
Matplotlib’s fill_between doesnt work with plot_date, any alternatives?
I want to create a plot just like this: The code: but with dates in the x axis, like this (without bands): the code: the problem is that fill_between fails when x values are date_time objects. Does anyone know of a workaround? DF is a pandas DataFrame. Answer It would help if you show how df is defined. What …
Ordered Logit in Python?
I’m interested in running an ordered logit regression in python (using pandas, numpy, sklearn, or something that ecosystem). But I cannot find any way to do this. Is my google-skill lacking? Or is this not something that’s been implemented in a standard package? Answer Update: Logit and Probit Ord…
How to replace negative numbers in Pandas Data Frame by zero
I would like to know if there is someway of replacing all DataFrame negative numbers by zeros? Answer If all your columns are numeric, you can use boolean indexing: For the more general case, this answer shows the private method _get_numeric_data: With timedelta type, boolean indexing seems to work on separat…
How to loop over grouped Pandas dataframe?
DataFrame: Code: I’m trying to just loop over the aggregated data, but I get the error: ValueError: too many values to unpack @EdChum, here’s the expected output: The output is not the problem, I wish to loop over every group. Answer df.groupby(‘l_customer_id_i’).agg(lambda x: ‘,…
How do you represent missing data in a Pandas DataFrame?
Does Pandas have an equivalent of R’s na (meaning not available)? If not, what is the convention for representing a missing value, as opposed to NaN which represents a mathematically impossible value such as a divide by zero? Answer Currently there is no NA value available in Pandas or NumPy. From the s…
Plot multiple boxplot in one graph in pandas or matplotlib?
I have a two boxplotes But I want to place them in one graph to compare them. Have you any advice to solve this problem? Thanks! Answer Use return_type=’axes’ to get a1.boxplot to return a matplotlib Axes object. Then pass that axes to the second call to boxplot using ax=ax. This will cause both b…
Check if dataframe column is Categorical
I can’t seem to get a simple dtype check working with Pandas’ improved Categoricals in v0.15+. Basically I just want something like is_categorical(column) -> True/False. We can see that the dtype for the categorical column is ‘category’: And normally we can do a dtype check by just …