dataframe

问题 When I try to iterate over a dataframe, somehow dtype is changed. dates = pd.date_range('20130101',periods=6) df = pd.DataFrame(np.random.randn(6,4),index=dates,columns=list('ABCD')) df A B C D 2013-01-01 -1.328046 -0.545127 -0.033153 1.190336 2013-01-02 -0.549147 0.447161 1.179931 0.397521 2013-01-03 -0.106707 -0.327574 -0.933817 -1.032949 2013-01-04 -0.519988 -1.007374 -0.794482 -1.757222 2013-01-05 -0.739735 1.220599 -1.387994 -0.116178 2013-01-06 0.262876 -0.679471 -0.568768 -0.277880 now

问题 Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 3 years ago . Improve this question Let's presume I have a data.fram called exprCore1 loaded in R-Studio, the df looks like this: measure qid value 1 p5 1 0.2 2 p100 1 0.8 3 map 1 0.22 4 p5 2 0.4 5 p100 2 0.5 6 map 2 0.32 Basically all want is every column in which the measurement method is "map"

问题 Like the title says. I am having trouble. for example I have a 2 column (V1,V2) dataframe with lots of rows, around 300,000. I know that max(df$V2) will give me the max value of that second column. Now that I know my max value, how can I get the entire row associated with that value. Thanks! 回答1: You have to write df[which.max(df$V2), ] If more than one row contains the max: i <- max(df$V2) df[which(df$V2 == i), ] 来源： https://stackoverflow.com/questions/36802736/trying-to-find-row-associated

问题 I want to add horizontal upper and lower limit line for Temparature timeseries plot. Lets say upper limit line at 30 and lower limit line at 10. df3.plot(x="Date", y=["Temp.PM", "Temp.AM"],figsize=(20,8)) 回答1: I think this solution can help you import matplotlib.pyplot as plt %matplotlib inline df3.plot(x="Date", y=["Temp.PM", "Temp.AM"],figsize=(20,8)) plt.axhline(30) plt.axhline(10) 回答2: plt.plot(df3['Date'], df3[["Temp.PM", "Temp.AM"]]) plt.axhline(30, color='r') plt.axhline(10, color='b')

问题 I know that test = [] for item in my_texts: test.append(item.encode('ascii', 'ignore').decode('ascii')) removes emojis from a list. But how can I remove emojis from a dataframe? When I try a = [] for item in goldtest['Text']: a.append(item.encode('ascii', 'ignore').decode('ascii')) I get only the last entry of goldtest. When I try the code on the whole dataframe, I get ''AttributeError: 'DataFrame' object has no attribute 'encode''' 回答1: This would be the equivalent code for pandas. It

问题 I want to sort all columns of a data frame in R by a column containing alphanumeric data. Here is an example data frame: R> dd <- data.frame(b = c("Hi", "Med", "Hi", "Low"), x = c("A", "D", "A", "C"), y = c(8, 3, 9, 9), z = c("A1", "A3", "A10", "A2")) 1 Hi A 8 A1 2 Med D 3 A3 3 Hi A 9 A10 4 Low C 9 A2 I would like to sort the entire data frame on column z. The desired output looks like this - with the info across columns staying consistent: 1 Hi A 8 A1 2 Low C 9 A2 3 Med D 3 A3 4 Hi A 9 A10

问题 I have a list of my.list that looks like this $S1 A B C D 1 101027 NA 0.48 NA 2 101031 1.50 1.30 0.8666667 3 101032 1.40 0.78 0.5571429 4 101127 NA NA NA 5 101220 9.30 7.30 0.7849462 $S2 A B C D 1 102142 NA 0.45 NA 2 102143 0.70 1.20 1.7142857 3 102144 NA 0.44 NA 4 102148 0.45 NA NA 5 102151 0.91 0.64 0.7032967 6 102152 0.78 NA NA I would like to remove any rows that have NA from the data frame of the list so it looks like $S1 A B C D 2 101031 1.50 1.30 0.8666667 3 101032 1.40 0.78 0.5571429

问题 I have a dataframe df with 6 fields A,B,C,D,E & F. My requirement is to create a new column G which is equal to the previous value(C) + previous value(D) + previous (G) - F. But this needs to be implemented at a group level through columns A & B (group by A & B). In case it is the first row within the group then the value in column G should be equal to E. Sample Df - A B C D E F 1 2 100 200 300 0 1 2 110 210 310 10 1 2 120 130 300 10 1 1 140 150 80 0 1 1 50 60 80 20 1 1 50 60 80 20 Output - A

问题 I have a pandas dataframe, in which some columns have numeric values while others don't, as shown below: City a b c Detroit 129 0.54 2,118.00 East 188 0.79 4,624.4712 Houston 154 0.65 3,492.1422 Los Angeles 266 1.00 7,426.00 Miami 26 0.11 792.18 MidWest 56 0.24 772.7813 I want to round off these numeric values to 2 decimal places, for which I am using: df = df.replace(np.nan, '', regex=True) After which df becomes: City a b c Detroit 129.0 0.54 2,118.0 East 188.0 0.79 4,624.47 Houston 154.0 0

问题 I have a pandas dataframe, in which some columns have numeric values while others don't, as shown below: City a b c Detroit 129 0.54 2,118.00 East 188 0.79 4,624.4712 Houston 154 0.65 3,492.1422 Los Angeles 266 1.00 7,426.00 Miami 26 0.11 792.18 MidWest 56 0.24 772.7813 I want to round off these numeric values to 2 decimal places, for which I am using: df = df.replace(np.nan, '', regex=True) After which df becomes: City a b c Detroit 129.0 0.54 2,118.0 East 188.0 0.79 4,624.47 Houston 154.0 0