如何从DataFrame
对象或 JuliaDBIndexedTable
对象中获取列名?这可能吗?
可重现的代码:
using JuliaDB
import DataFrames
DF = DataFrames
# CREATES AN EXAMPLE TABLE WITH JULIADB
colnames = [:samples, :A, :B, :C, :D]
primary_key = [:samples]
coltypes = [Int[], Float64[],Float64[],Float64[],Float64[]]
sample_sizes = [100,200,300]
example_values = (1, 0.4, 0.3, 0.2, 0.1)
mytable = table(coltypes..., names=colnames, pkey=primary_key) # initialize empty table
# add some data to table
for i in sample_sizes
example_values = (i, 0.4, 0.3, 0.2, 0.1)
table_params = [(col=>val) for (col,val) in zip(colnames, example_values)]
push!(rows(mytable), (; table_params...)) # add row
mytable = table(mytable, pkey = primary_key, copy = false) # sort rows by primary key
end
mytable = table(unique(mytable), pkey=primary_key) # remove duplicate rows which don't exist
# MAKES A DATAFRAME FROM JULIADB TABLE
df = DF.DataFrame(mytable)
例如,给定上面的代码,如果:E
在mytable
or中有一列,您将如何使用条件检查df
(为了添加这样的列,如果它尚不存在)?
最终,我正在寻找与以下 Python 代码等效的 Julia:
if 'E' in df.columns:
# ...
else:
# ...