py-datatable

问题 In pydatatable, I'm trying to modify a column values specifying a condition in i i.e DT[i=="text", j="some"] sample DT: py_DT= dt.Frame({'crossing':['ABC','A','B','B','A','A','ABC'], 'total' :[2,4,5,6,8,10,12]}) Here i would like to replace crossing value 'ABC' with 'A' only, for that i have written a below sample code, Attempt 1: py_DT[f.crossing=="ABC", f.crossing=="A"] Attempt 2: py_DT[f.crossing=="ABC", update(f.crossing=="A")] None of these attempts were worked out, is there any other

问题 In pydatatable, I'm trying to modify a column values specifying a condition in i i.e DT[i=="text", j="some"] sample DT: py_DT= dt.Frame({'crossing':['ABC','A','B','B','A','A','ABC'], 'total' :[2,4,5,6,8,10,12]}) Here i would like to replace crossing value 'ABC' with 'A' only, for that i have written a below sample code, Attempt 1: py_DT[f.crossing=="ABC", f.crossing=="A"] Attempt 2: py_DT[f.crossing=="ABC", update(f.crossing=="A")] None of these attempts were worked out, is there any other

问题 In pydatatable, I'm trying to modify a column values specifying a condition in i i.e DT[i=="text", j="some"] sample DT: py_DT= dt.Frame({'crossing':['ABC','A','B','B','A','A','ABC'], 'total' :[2,4,5,6,8,10,12]}) Here i would like to replace crossing value 'ABC' with 'A' only, for that i have written a below sample code, Attempt 1: py_DT[f.crossing=="ABC", f.crossing=="A"] Attempt 2: py_DT[f.crossing=="ABC", update(f.crossing=="A")] None of these attempts were worked out, is there any other

问题 In pydatatable, I'm trying to modify a column values specifying a condition in i i.e DT[i=="text", j="some"] sample DT: py_DT= dt.Frame({'crossing':['ABC','A','B','B','A','A','ABC'], 'total' :[2,4,5,6,8,10,12]}) Here i would like to replace crossing value 'ABC' with 'A' only, for that i have written a below sample code, Attempt 1: py_DT[f.crossing=="ABC", f.crossing=="A"] Attempt 2: py_DT[f.crossing=="ABC", update(f.crossing=="A")] None of these attempts were worked out, is there any other

来源： https://stackoverflow.com/questions/64286667/python-datatable-sum-groupby-column-0

问题 I have a data frame with two columns as shown below, DT_EX = dt.Frame({'film':['Don','Warriors','Dragon','Chicago','Lion','Don','Chicago','Warriors'], 'gross':[400,500,600,100,200,300,900,1000]}) Here in first case i would like to filter the observations whose film is Don or Chicago as written in below code, DT_EX[((f.film=="Don") | (f.film=="Chicago")),:] In a second i would apply filter for 3 values as, DT_EX[((f.film=="Don") | (f.film=="Chicago") | (f.film=="Lion")),:] In case of filtering

问题 I have a data frame with two columns as shown below, DT_EX = dt.Frame({'film':['Don','Warriors','Dragon','Chicago','Lion','Don','Chicago','Warriors'], 'gross':[400,500,600,100,200,300,900,1000]}) Here in first case i would like to filter the observations whose film is Don or Chicago as written in below code, DT_EX[((f.film=="Don") | (f.film=="Chicago")),:] In a second i would apply filter for 3 values as, DT_EX[((f.film=="Don") | (f.film=="Chicago") | (f.film=="Lion")),:] In case of filtering

问题 What is the data.table for python equivalent of %like%? Short example: dt_foo_bar = dt.Frame({"n": [1, 3], "s": ["foo", "bar"]}) dt_foo_bar[re.match("foo",f.s),:] #works to filter by "foo" I had expected something like this to work: dt_foo_bar[re.match("fo",f.s),:] But it returns "expected string or bytes-like object". I'd love to start using the new data.tables package in Python the way I use it in R but I work a lot more with text data than numeric. Thanks in advance. 回答1: Since version 0.9

问题 What is the data.table for python equivalent of %like%? Short example: dt_foo_bar = dt.Frame({"n": [1, 3], "s": ["foo", "bar"]}) dt_foo_bar[re.match("foo",f.s),:] #works to filter by "foo" I had expected something like this to work: dt_foo_bar[re.match("fo",f.s),:] But it returns "expected string or bytes-like object". I'd love to start using the new data.tables package in Python the way I use it in R but I work a lot more with text data than numeric. Thanks in advance. 回答1: Since version 0.9