concatenation

问题 For list of strings, define the multiplication operation in as concatenating here: l1 = ['aa', 'bb', 'cc'] l2 = ['11', '22'] l3 = l1 op l2 Expected output: l3 = ['aa11', 'aa22', 'bb11', 'bb22', 'cc11', 'cc22'] Simply we can use for l in l1: for ll in l2: l3.append(l+ll) But I'd be grateful to hear a pythonic solution. 回答1: from itertools import product l1 = ['aa', 'bb', 'cc'] l2 = ['11', '22'] l3 = [x+y for (x,y) in product(l1,l2)] print(l3) But it's effectively the same thing as what you're

问题 I am trying to concatenate two dataframes, above and below. Not concatenate side-by-side. The dataframes contain the same data, however, in the first dataframe one column might have name "ObjectType" and in the second dataframe the column might have name "ObjectClass". When I do df_total = pandas.concat ([df0, df1]) the df_total will have two column names, one with "ObjectType" and another with "ObjectClass". In each of these two columns, half of the values will be "NaN". So I have to

问题 I am trying to concatenate two dataframes, above and below. Not concatenate side-by-side. The dataframes contain the same data, however, in the first dataframe one column might have name "ObjectType" and in the second dataframe the column might have name "ObjectClass". When I do df_total = pandas.concat ([df0, df1]) the df_total will have two column names, one with "ObjectType" and another with "ObjectClass". In each of these two columns, half of the values will be "NaN". So I have to

问题 I am trying to concatenate two dataframes, above and below. Not concatenate side-by-side. The dataframes contain the same data, however, in the first dataframe one column might have name "ObjectType" and in the second dataframe the column might have name "ObjectClass". When I do df_total = pandas.concat ([df0, df1]) the df_total will have two column names, one with "ObjectType" and another with "ObjectClass". In each of these two columns, half of the values will be "NaN". So I have to

问题 I am trying to concatenate two dataframes, above and below. Not concatenate side-by-side. The dataframes contain the same data, however, in the first dataframe one column might have name "ObjectType" and in the second dataframe the column might have name "ObjectClass". When I do df_total = pandas.concat ([df0, df1]) the df_total will have two column names, one with "ObjectType" and another with "ObjectClass". In each of these two columns, half of the values will be "NaN". So I have to

问题 I'm concatenating 2 video files 00000 and 00001: ffmpeg -y -f concat -safe 0 -i file_list.txt -loglevel error -c copy test.mp4 file_list.txt: file '00000.mp4' file '00001.mp4' 00000.mp4: Duration: 00:00:00.42, start: 0.000000, bitrate: 204 kb/s Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 182 kb/s, 60 fps, 60 tbr, 15360 tbn, 120 tbc (default) 00001.mp4: Duration: 00:00:01.63, start: 0.000000, bitrate: 58 kb/s Stream #0:0(und): Video: h264 (High) (avc1 /

问题 This question already has answers here : Converting a sequence of numbers in an array to range of numbers (12 answers) Closed 26 mins ago . I want to concatenate a sequence of numbers in a readable string. Consecutive numbers should be merged like this '1-4' . I'm able to concatenate an array with all the numbers into a complete string but I'm having trouble combining / merging consecutive numbers. I tried comparing the previous and next values with the current one in the loop with several if

问题 This question already has answers here : Iterate over all combinations of values in multiple lists in Python (2 answers) Closed 4 years ago . I need to concatenate 2 different lists of strings in python. for example: list1 = ['A','B','C'] list2 = ['D', 'E'] I want to obtain list3 = ['AD', 'AE', 'BD', 'BE', 'CD', 'CE'] I've tried: list3 = zip(list1,list2) And it returns list3 = [('A','D'), ('B','E')] I've also tried: list(itertools.product(list1, list2)) But it returns [('A','D'),('A','E'),...

问题 Hi the following code only gives me the data from the last file.There is a issue with the concat or the for loop. I am reading data from 2 files. each should contain nearly 350 rows 3 columns that agree the condition in the for loop. So at the end data frame should give nearly 700 by 3 data frame. but it only shows data from the last file. import glob from pathlib import Path path = Path(r'C:\Users\PC\Desktop\datafiles') filenames = path.glob('*.txt') toconcat = [] for i in filenames: data1 =

问题 Say I have a folder which have multiple excel files with extension xlsx or xls , they share same header column a, b, c, d, e except some empty sheet in several files. I want to iterate all the files and sheets (except for empty sheets) and concatenate them into one sheet of one file output.xlsx . I have iterated through all excel files and append them to one file, but how could I iterate through all the sheets of each files if they have more than one sheets? I need to integrate two block of