{"kind":"task","effective_mode":"full","benchmark":{"kind":"benchmark","effective_mode":"full","slug":"ds-1000","formal_name":"DS-1000","introduction":"DS-1000 builds 1,000 data-science problems from real StackOverflow questions across seven libraries including NumPy, Pandas and Matplotlib. The problems are perturbed so that recalling the original answer does not solve them.","introduction_ja":"","introduction_en":"","category":"Category not supplied","task_count":null,"acquisition_status":"Acquisition status not supplied","official_url":"https://ds1000-code-gen.github.io/","indexing_mode":"index","profile":{"resources":[],"task_format":"","scoring":"","metric":"","size":"","answer_access":"","license":"","citation":"","maintainer":"","released":"","why_hard":"","related":[],"history":"","construction":"","limitations":"","saturation":"","scores":[]}},"task_id":"dfa201c5-00e4-59e1-a9fc-ec70df06540a","task_key":"default--test--255","task_revision_id":"1","upstream_id":"255","short_description":"I have a dataframe with one of its column having a list at each index. I want to…","config":"default","split":"test","body":"{\"library\":\"Pandas\",\"prompt\":\"Problem:\\nI have a dataframe with one of its column having a list at each index. I want to reversed each list and concatenate these lists into one string like '3,2,1,5,4'. I am using\\nids = str(reverse(df.loc[0:index, 'User IDs'].values.tolist()))\\n\\nHowever, this results in\\n'[[1,2,3,4......]]' which is not I want. Somehow each value in my list column is type str. I have tried converting using list(), literal_eval() but it does not work. The list() converts each element within a list into a string e.g. from [12,13,14...] to ['['1'',','2',','1',',','3'......]'].\\nHow to concatenate pandas column with list values into one string? Kindly help out, I am banging my head on it for several hours.\\n\\nA:\\n<code>\\nimport pandas as pd\\n\\ndf = pd.DataFrame(dict(col1=[[1, 2, 3],[4,5]]))\\n</code>\\nresult = ... # put solution in this variable\\nBEGIN SOLUTION\\n<code>\\n\"}","display_format":"code","language":"","answer_status":"published","assets":[],"source_url":"https://ds1000-code-gen.github.io/","history":"initial import","indexing_mode":"index","subproblems":[],"grids":[]}