from_csv('myfile. Mar 27, 2024 · Python NumPy loadtxt() function is used to load the data from a text file and store them in a ndarray. csv') #if necessary change default parameter sep=',' df = pd. Noted that the data read has to have an equal number of elements in all of the numbers of rows contained. import Isn't it that np. csv supports tab delimited files. DataFrame(data) import matplotlib. A csvfile must be an iterable of strings, each in the reader’s defined csv format. 5 first 100 1 . 日本語交じりのファイルをnp. – Max L. So work: df = pd. reader(csvfile, dialect='excel', **fmtparams) ¶. File, filename, list, or generator to read. reader (with more lines of code). loadtxt("cov. csv file with both string and integer - containing columns. import numpy as np from io import StringIO data = """'x'\t'y' '1'\t'2. strip(b"'")))) ) Using csv Aug 26, 2014 · 27. csv file in the above specified location and it did not work. 数组中没有输出 id，cpu，mem等信息，因为默认skiprows=0会将首行过滤. If the filename extension is . – import pandas as pd data = pd. This will read in the csv and convert the numeric columns into a numpy array for scikit_learn, then modify the order of columns and write it out to an excel spreadsheet: import numpy as np. 10, np. listdir (os. loadtxt in Colab. UnicodeDecodeError: 'cp932' codec can't decode byte 0xef in position 0: illegal multibyte sequence Feb 1, 2024 · この記事では、loadtxtの基本的な使い方と応用例について詳しく説明します。 loadtxtの基本的な使い方. csv',delimiter=',', skiprows=0,usecols=(0,),unpack=False) I use numpy. Note that generators must return bytes or strings. Could be to optimize the array and make it N x M, instead of having multiple column lengths. Use the dtype=object constructor: [2011, 12, 20, A, S, 1200. 0]], dtype=object) Such an array will not be as efficient as an array of primitive values, but it will support all operations normally supported by numpy arrays, while still providing for different types in different columns. The strings in a list or produced by a generator are treated as lines. read_csv is about the same time. data = np. load a certain number of rows from csv with numpy. 2) Use numpy's genfromtext. loadtxt(open(path_to_data, "rb"), delimiter=",", skiprows=1, usecols=[1:]) Jul 9, 2017 · If no parameter names in read_csv then first row data create columns of df. I am using anocanda notebook on macbook. Opening the file, and passing the lines through your own filter script also works fine. – DSM Commented May 8, 2013 at 16:13 Apr 25, 2014 · Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand I am using the numpy. loadtxt() function, simplified as np. loadtxt () to ONLY load the columns you wish. Load data from a text file. datetime64. loadtxt ("weather. 7,3. txt') # In ra dữ Aug 28, 2018 · I have a . savetxt () to write an ndarray as a CSV file. e. Aug 21, 2019 · For more information on the numpy. As @chrisb said, pandas' read_csv is probably faster than csv. This is more efficient than using dtype=None, that asks np. data = numpy. Jan 31, 2021 · numpy. csv --- CSV ファイルの読み書き — Python 3. The csv file contains grades for a random number of students and a random number of assignments. read_csv(input_file, header = 0) 3 days ago · The csv module defines the following functions: csv. Currently I am more concerned about whether it's me doing something wrong. But processing the lines before passing them to loadtxt is quite acceptable. genfromtxt('info. genfromtxt to guess the datatype for you. I don't think you will find something better to parse the csv (as a note, read_csv is not a 'pure python' solution, as the CSV parser is implemented in C). read_csv('your_file',sep='\t') It can be converted to a NumPy array if you prefer that type with: import numpy as np arr = np. The second one was pretty fast but I was getting errors later in my project (I solve some PDEs with finite element method and while reading the coordinates with either my parser or loadtxt I get the correct result Mar 3, 2015 · import numpy as np import datetime import string time_1=np. loadtxt(), with this informative article. docstring: In NumPy, the loadtxt() method loads data from a text file. loadtxt is best illustrated using an example. hpaulj. I am using iter_loadtxt as seen on stack overflow to load > 600MB text files. delimiter （可选）：在从文本中创建数组时要考虑的分隔符，默认为空白。. 创建一个csv文件（test_csv. read_csv. loadtxt(file, dtype=np. load multiple times on the same file handle, if all data has already been read. loadtxtで読み込みます。. If you don't need to do any type of numerical analysis, you can import the data as strings. Return a reader object that will process lines from the given csvfile. input_file = "mydata. File "jpk_outfile_to_LOG_timeV4. genfromtxt will either. Aug 31, 2018 · When I read the file using loadtxt, the header is ignored and only the data is saved in my new array. Assuming your columns are tab separated, this should do the trick (adapted from this question ): df = DataFrame. loadtxt(open(filein, "rb"), delimiter=",", skiprows=1) For various reasons I'd like to continue to use np. I want to plot both sets onto the same graph. 3 So as given in the docs , all I had to do was use the skiprows parameter Dec 3, 2012 · As said in the comments numpy. loadtxt('datafile1. The python csv module has some sort of quote awareness. import StringIO. txt', max_rows=5) # Load specific columns data = np. char. Using numpy. The docs for the function you could use are here. Using converter functions. genfromtxt(path_to_csv, dtype=float, delimiter=',', names=True) Please note the dtype=float, that will convert your data to float. I want one dictionary. csv',delimiter=",") why is this not working I copied the data. You could try pandas. loadtxt), skiprows is only useful for skipping the first N rows. Each row in the text file must have the same number of values. loadtxt('test. DictWriter classes, but I could only figure out how to generate a new dictionary for each row. All the function Apr 19, 2018 · In summary, my main goal is to find a programmatic way to change the Excel file type/encoding to something I can import into Python 3 using existing packages with CSV support. pyplot as plt x = data[0] y = data[1] plt. bz2, the file is first decompressed. OSError: Macintosh HD⁩\\Users⁩\\binhao⁩\\Downloads⁩\\Iris_data. pd. csv', sep=';') print (df) Date low open close 0 2015-08-08 266. 2 ms ± 4. nan for float, -1 for int). This tells me that the kwarg 'skiprows' is not skipping the header, it's skipping the first row of comments. loadtxtとは. The first set contains about 100 entries and the second set contains about 75. csv If I try to import this using . loadtxt (v1. 语法: numpy. But in the case of the data I have attached here I only need every 2nd line of data after the first skipped line, i. The use of np. decode. Sep 22, 2016 · Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand Jan 8, 2018 · numpy. loadtxt () This function is used in Python language in order to get the data loaded from various text files. csv），文件内容是：. You can load your CSV data using Pandas and the pandas. npy file. csv’) Parameters: fname: The file to read from. loadtxt ()读取，此时使用文件的相对地址进行读取：. read_csv with skip_blank_lines=True should handle that for you. columns) Index(['Date', 'low', 'open Apr 16, 2019 · You have to give the specific path to the csv file, for example if the file is in C:\User\Files\clicks. ¶. csv and then 0 but I don't get why it doesn't go through i = 1, i=2 or show the rest of the CSV file data? What I'm getting: 1. He already had the right dtype for column 0 (S10); the problem is that his dtype has a different shape than the result he expects—he's specifying a dtype for a 4-column array, and then trying to read only 1 column into it. csv', delimiter=',', usecols=[0,1,2,3], invalid_raise=False) Jun 8, 2023 · Pythonの標準ライブラリのcsvモジュールを使うと、CSVファイルの読み込み・書き込み（新規作成・上書き保存・追記）ができる。. But, if you have to load/query the data often, a solution would be to parse the CSV only Jan 22, 2024 · In NumPy, you can use np. gz or . import numpy as np. 0 last 3000 then it is a space-delimited file, so you should use read_csv. Nov 9, 2023 · Method 1: NumPy read csv file using genfromtxt in Python. load ()用于从文本文件中加载数据，其目的是为了快速读取基本的文本文件。. loadtxt('TS. The following is the syntax: Both the functions return a numpy array. Supply the delimiter argument to reader:. loadtxt method to import the matrix formed from the specified columns. genfromtxt () to read a CSV file as an array ( ndarray ), and np. The first one worked great but it's speed was even worse than mine. genfromtxt ('float. I copied the csv file in the jupyter folder, but it still did not work What is wrong? The first column of the csv file contains unique keys and the second column contains values. loadtxt () function. This file can be downloaded as eg6-a-student-data. 04 266. csv". integer, and loadtxt prepares to deal with that column as an integer with the following: typ = dtype. loadtxt("Macintosh HD⁩\\Users⁩\\binhao⁩\\Downloads⁩\\Iris_data. The purpose of loadtxt() function is to be a fast reader for simple text files. ") – You can use the numpy functions genfromtxt() or loadtxt() to read CSV files to a numpy array. 0. want to load is 'weather' txt file ", so I would make the same asumption as you did. import csv txt_file = r"mytxt. loadtxt('test', dtype=float, delimiter=',') Nov 23, 2023 · Pythonには、CSVファイルを読み込むためのライブラリとして、numpyとpandasがあります。本記事では、numpyとpandasを使ったCSVファイルの列指定による読み込み方法と、行指定による読み込み方法について解説します。 numpyを使ったCSVファイルの列指定による読み込み Oct 15, 2022 · Load data stored in a text file with Numpy Loadtxt. csv") May 17, 2021 · Somehow numpy in python makes it a lot easier for the data scientist to work with CSV files. #. 3,2. csv', dtype='str,int', delimiter=',', usecols=(0, 1), unpack=True) Sep 27, 2013 · 1. 0 280. loadtxt ('data. – Learn how to read txt files using the numpy. astype(str)作用是改变np. loadtxt () 함수에 dtype 매개 변수 설정. of 7 runs, 10 loops each) answered Sep 8, 2018 at 19:59. loadtxt (): import numpy as np # Đọc dữ liệu từ file văn bản data = np. Dưới đây là một ví dụ cơ bản về cách sử dụng numpy. ExcelFile to read your data (not sure if this will work as you didn't gave an example. 4 6. Data-type of the resulting array; default: float. loadtxt. I tried to use the csv. I need to use numpy. 82 print (df. To skip rows in the middle of the file, you'll need to form an iterator which yields only the lines you want. loadtxt関数 はNumPyのファイル読み込み用関数です。 主に、 CSV/TSV などの 単純な構造のファイルを読み込む のに使います。 もしも前処理などを効率的に行いたい場合は、Pandasで読み込んだ方が便利だと（僕は）思うので、以下の記事を読んで Aug 24, 2022 · The first two columns (0 and 1) comprise the latitude and longitude of the first set, and the next two columns (2 and 3) comprise the second set. See the docs for more info. 6,9. data', delimiter=',') The problem is that the missing values break loadtxt (I get a "ValueError: could not convert string to float:", no doubt because of the two or more consecutive delimiters). loadtxt よりも複雑な条件付けができるデータ読み込み用のメソッドです。主に欠損値に対応することを目的としているようです。パラメータはnp. # Student data collected on 17 July 2014. python. if issubclass(typ, np. 使用delimiter=',作为csv数据的分隔符' 实例2 NumPy seems great for reading in columns of data with only a single delimiter, but the parenthesis seem to ruin any attempt at using numpy. So, for example, if you have row-and-column data that’s stored in a text file, where the numbers are separated by commas (a so-called csv file), you can use Numpy loadtxt to load the data into your Python environment. csv') 98. Using PySpark. Jan 8, 2018 · There is also read_csv in Pandas, which is fast and supports non-comma column separators and automatic typing by column: import pandas as pd df = pd. With non Mar 31, 2022 · csvの空白の欄を欠損値nanを入れて読み込みたい. Column1,Column2,Column3 5. loadtxt () 함수를 사용하여 txt 파일을 읽습니다. Example import numpy as np Say the name of the file is info. loadtxt (fname, dtype=’float’, comments=’#’, delimiter=None, converters=None, skiprows=0, usecols=None, unpack Oct 7, 2019 · I cannot load a csv file using the numpy loadtxt function. str, delimiter='\t', skiprows=1) is that it uses python objects (strings) instead of float64, which is very memory inefficient. Suraj Joshi 2023년1월30일. May 17, 2022 · loadtxt (and genfromtxt) accept input from anything that can feed them lines. Nov 8, 2015 · dynamically works for inputs with and without trailing commas (without specifying) I went with using numpy. Description. FH = np. Note that generators should return byte strings for Python 3k. Starting Numpy 1. When calling np. There must be something wrong with the file format or something else. Using NumPy's loadtxt method. Feb 15, 2022 · Để sử dụng hàm numpy. 4 ドキュメント. genfromtxt(filename, delimiter=',', names=True) Here, Name. cov = np. e. It seems this solution is also similar just genfromtext is replaced with csv. np. Another thing you could try is adding the line print (os. I've edited the post above to show one such way. csv") The first element is in scientific notation which causes a failure See full list on likegeeks. The major is to act as a fast text reader specifically for unified textual files. csv" # use 'with' if the program isn't going to immediately terminate # so you don't leave files open # the 'b' is necessary on Windows # it prevents \x1a, Ctrl-z, from ending the stream prematurely Jan 18, 2017 · Could be to warn users that the CSV file might be corrupt. genfromtxt instead, overwriting its delimiting behaviour to ignore the last element if it's empty: import numpy as np. If your text file is similar to the following (note that each column is separated from one another by a single space character ' '): 0 1. loadtxt call to print out all the files in the current working directory and see if you see your file. txt. genfromtxt (‘data. 7 ms per loop (mean ± std. load() in Python is used load data from a text file, with aim to be a fast reader for simple text files. Python Data Science Handbook: full text in Jupyter Notebooks - jakevdp/PythonDataScienceHandbook Dec 22, 2021 · csv文件数据如下： 因为csv文件里面的日期是字符串，后面的为数值，数据类型不同不能一次性读取到一个numpy数组里面，否则会报类型错误， 所以分为两次读取，t1读取数据（即第1、2、3、4、5列），t2读取字符串格式的日期（第0列） 在读取字符串时，最后的. loadtxt ¶. loadtxt(filename,skiprows=header,dtype=str) By utilizing StringIO, we can simply read the file and replace every instance of ':' with " ", without having to modify any of the other code. loadtxt () or np. How can I do that? Right now I am trying to do the following: data = np. values # the array you are interested in. read_csv('data. Jan 8, 2018 · Either import functions explicitly from numpy import loadtxt or use the standard abbreviation, import numpy as np and then np. In other words, it is not quote sensitive. genfromtxt/loadtxt. 2 import matplotlib. reader/numpy. You can use pandas read_table Apr 1, 2023 · Uses of Numpy. a=readjpk(filename,lateral,vertical,xpos) . loadtxt function: data = numpy. df = pd. lib import npyio. show() this is my data . edited May 23, 2017 at 11:33. 예제 코드: txt 파일을 읽는 동안 numpy. genfromtxt. 4,2. 3 This is correct, but I think it needs to be a bit clearer. I cannot load file as 'weather. Occasionally the program generating the files make a bad write to the text file and iter_loadtxt barfs: File "<stdin>", line 1, in <module>. Mar 25, 2022 · In situations where you only need a subset of the data or want to preview a portion of a large file, loadtxt provides parameters to load partial data: # Load only the first 5 rows data = np. Consider the following text file of data relating to a (fictional) population of students. datetim64 is a subclass of numpy. genfromtxt takes an optional parameter max_rows which limits the number of lines to read. csvというモジュール名だが、カンマ区切りに限らずタブ区切り（TSV Sep 25, 2023 · But the it only shows the dataset for the first CSV file and I think the loop ends at i=0 because the return shows the data for data1. Pandas can do that for you. I am using numpy. Feb 13, 2019 · 各个参数的详细用法. loadtxt('C:\User\Files\clicks. 02 . genfromtxt is a bit faster than loadtxt: In [907]: timeit data = np. array中所有数据 Reading text and CSV files# With no missing values# Use numpy. loadtxt cannot read Excel files. loadtxt(). 3. txt',sep='\s+',header=None) data = pd. loadtxt( 'data. 11. read_csv() function. For this you'll need to know the correct number of columns in advance. return a masked array masking out missing values (if usemask=True), or. Note that each row in the text file must have the same number of values. plot(x, y,'r--') plt. Is there a clever way to read in the file with Python, or is it best to just read the file, remove all of the parenthesis, then feed it to NumPy? May 24, 2013 · So in my case the csv file had column names written in the first row. txt" csv_file = r"mycsv. bool_): return lambda x: bool(int(x)) Feb 11, 2015 · This issue has been discussed before. csvデータをnumpyのloadtxtを使っていつも読み込んでいるのですが、今回使用しているファイルが添付の写真のように空白になっている部分が多く、エラーが発生してしまっています。. Mar 1, 2019 · loadtxt is a simple Python file reader - readline, split, collect list of lists, pandas. loadtxt () 구문 : 예제 코드: NumPy numpy. Apr 5, 2019 · In JupyterLab, when I have the notebook file and the associated csv files in the same directory, it is easy to import the data using numpy's loadtxt function as follows: import numpy as np. numpy. Using the CSV module. def _cutoff_last(func, *args, **kwargs) -> list: line = func(*args, **kwargs) if line and The initial loadtxt line looked like this: import numpy as np. loadtxt () trong Python, bạn cần import thư viện NumPy và sau đó gọi hàm này với các tham số tương ứng. 10 of numpy). 41795. I am trying to load some data stored in a CSV file where the headers are in the first column. 数组中的值都是String类型，使用dtype=str. import pandas as pd. loadtxt should be faster than np. Csv中有10行数据，但是数组中保存了5行，因为使用max_rows=5. savetxt(file_name, array, delimiter=",", header='x,y,z, data from monte carlo simulation') data = np. 5 thirteenth 20 2 3. Dec 11, 2018 · numpy. Mar 20, 2017 · Now, to extract data from that I use the following code to get the decimal values: y = np. 5'""" arr = np. (1,3,5,7,9) for the first plot with five x-values, and Mar 18, 2013 · 7. Syntax: data = np. type. The pandas reader is also quote aware. loadtxt('1. txt", ~) too, but nothing is changed. loadtxt. Have you tried the code posted in the accepted answer? (Its below the diagrams under "Alternately, consider something like the following. 82 1 2015-07-08 233. loadtxt () in Python. File, filename, or generator to read. loadtxt (): シンプルなテキストファイルからデータを効率的に読み込む場合に使用します。. genfromtxt? I haven't tried python csv module yet because loading csv file is a really frequent thing I do and with the csv module, the coding is a little bit verbose But I'd be happy to try it if that's the only way. Dec 17, 2019 · That would indicate that the file is in the right place and that this should work. 00 . We will wait to wait and see if the Asker gives any clarifications. . read_csv('file. genfromtxt is a powerful function provided by NumPy in Python, designed to handle the loading of data from text files, with a particular focus on CSV files. NumPy. However, it always has . Create a memory-map to an array stored in a file on disk. loadtxt と共通のものが多いので、新しく覚えなければいけないことは、そう多くはありません。 Feb 3, 2017 · I want to load a csv file into python. 使用numpy. csv', so I've already tried 'np. Nov 23, 2017 · np. csv, the correct command should be: data = np. Create or load a memory-mapped . loadtxt('C:\\Users\\hp\\Desktop\\data. Sep 9, 2012 · data = np. 6). How can I access the header as it has important information I want to save as a string. 03 May 13, 2024 · loadtxt () と genfromtxt () の使い分け. from numpy. 1 93 30 96 60 84 90 84 120 48 150 38 180 51 210 57 240 40 270 45 300 50 330 75 360 80 390 60 420 72 450 67 480 71 510 7 540 74 570 63 600 69 Jun 10, 2014 · At first, I thought of loading the csv file in both loadtxt and genfromtext and accessing both numpy array and column names but that is taking too much time. loadtxt(StringIO(data), dtype=float, delimiter="\t", skiprows=1, converters=dict. Use a Pandas dataframe. txt', skip_header=100, max_rows=50) I tried the solution and it is an enhancement of the loadtxt for simple data (I do not know the content of your file). encoding（可选）：用于对输入 Jul 1, 2019 · The problem might arise because of the meta-text in the . CSV' ,delimiter= ',' ,skiprows= 1, encoding= "utf-8_sig" ) エラーが発生. Additionally, if someone has any idea why numpy. Note that the numpy genfromtxt() function is a more versatile reader compared to loadtxt() which aims to be a fast reader for simply formatted files. Jan 11, 2017 · The problem with np. ValueError: could not convert string to float: the csv file like this . The genfromtxt () method is used to import the data from a text document. DictReader and csv. So basic Python code, read a line, pass it on, or split it and pass the two lines separately. loadtxt(raw_data, delimiter=",", dtype='str') . Syntax: numpy. Without using any library. loadtxt() function see the API documentation (version 1. Nov 30, 2013 · No, as is stated in help(np. csv not found. Oct 8, 2015 · If the csv has a mix of strings and numbers, this converters approach will be easier to use than the np. Jul 18, 2016 · Searching online I found numpy's loadtxt and pandas read_csv. array(df) If you don't want the dtype you've set (where I see no reason why you wouldn't want it), you can use skiprows and usecols parameters of np. genfromtxt () function. 1. loadtxt to read a CSV file. Oct 5, 2018 · python - using numpy loadtxt reading a csv file with different data types for each column. We can specify how to handle the missing values if there are any. py", line 296, in makeLOGtimefile. There isn't a parameter in loadtxt (or genfromtxt) that does what you want. NumPyのloadtxt関数を使用して、テキストファイルからデータを読み込む基本的な方法を紹介します。 Sep 14, 2014 · Alternatively, you can convert the tab delimited file to csv first. Or you can use the csv module to load your data in and then pass that data to numpy. If you need it to work normally for multidimensional array and to keep one-dimensional when you read onedimensional array, I thik that the best way is to read normally with loadtxt and reshape you arrays in a second phase, converting them to monodimensional if they are pure numbers The file contains an object array, but allow_pickle=False given. The two ways to read a CSV file using numpy in python are:-. Syntax: Aug 5, 2015 · 2. csv', delimiter = ',') then I get the following error: ValueError: Some errors were detected ! Line #4 (got 1 columns instead of 5) If I use, data = numpy. Just specify the converter for each string column. I've loaded the csv file into Python using numpy. loadtxt('file. Numpy loadtxt enables you to load numeric data that’s stored in a text file. Jul 22, 2015 · data = np. txt file that is not really written there but is copied when its content is loaded somewhere. Each row of the csv file represents a unique key, value pair within the dictionary. csv',comments='#',delimiter=',',skiprows=1) But, I'm getting an error: ValueError: could not convert string to float: x. csv’) 参数: fname：加载数据的文件名。. I was wondering if there is a way to load all the columns except the first? I know that it is possible to choose the columns we want to load. I want python to delete the header and the first column (Name of student) and this is my code: May 1, 2013 · When numpy sees your dtype format of datetime [64], it prepares to output a column of type numpy. My csv file is of 5MB, so I wanted one library that could do both at the same Dec 22, 2021 · 我们把csv三列的数据分别赋值给了x,y,z, 使用unpack=True. as showed above. Sep 30, 2022 · Read CSV files Using NumPy genfromtxt () method. With missing values# Use numpy. The numpy. getcwd ())) above the np. I think it is better to first import your text in an array or a string and then split it and save into the dataframe specifically when your data is not too large. genfromtxt (): 複雑な構造を持つテキストファイル、欠損値を含むファイル、複数のデータ型を含むファイルを読み込む場合に使用し May 6, 2024 · np. dev. txt', sep='\t') array = df. pyplot as plt. loadtxt () 함수에 delimiter 매개 변수 numpy. Note that generators should return byte strings. fill in the missing value with the value specified in filling_values (default is np. Jan 11, 2021 · numpy【loadtxtで日本語ファイルを読む】. Load CSV File With Pandas. I often demonstrate them with a list of lines obtained from the copy-n-paste. @Ellen are both the python script and the Sep 8, 2018 · This 2x improvement over loadtxt seems typical of variations on this. The output will be a structured array, where you can access individual columns by their name. Edit: np. A csvfile is most commonly a file-like object or list. csv', delimiter = ',', skip_footer = 1) Mar 20, 2018 · import numpy as np data=np. loadtxt can't import a text file with a UTF-8 encoding (but can for ANSI encoding) that would be great too! I'm trying to load a file that represents a 2D matrix with numpy loadtxt. May 25, 2019 · The original text said ". If you want to perform numerical operations on your data, you're going to need to remove the Time Freq header, and convert your times to numbers. com In short, read_csv reads delimited files whereas read_fwf reads fixed width files. txt', usecols= (0, 2)) The max_rows parameter limits the number of rows The script that I thought would work for this situation looks like: import numpy as np. fromkeys([0, 1], (lambda s: float(s. loadtxt(‘data. Your result will be a NumPy array with a shape of (n, 2), not (n, 3) that you thought you'd have (where n is your number of rows). fname ：指定需要读取的CSV文件（从某种意义来说，CSV文件属于txt文件，详细可百度）地址即可完成最简单的读取操作，如下：. csv', delimiter=',', dtype='int', skiprows=1) This should work Jun 10, 2017 · numpy. genfromtxt('data. txt), skiprows=1, usecols=(2,)) And then use that data for plotting. csv or . 在Python中， numpy . genfromtxt は、np. filein = "testfile. # comma delimited is the default. g. Combined with the other optional parameter skip_header, you can select a slice of your file (for instance lines 100 to 150): import numpy as np. tt dn jd ep oi wf lw pf yf sg