Programming Articles - Page 1408 of 3366

Write a program in Python to perform flatten the records in a given dataframe by C and F order

Vani Nalliappan
Updated on 25-Feb-2021 06:06:13

158 Views

Assume, you have a dataframe and the result for flatten records in C and F order as, flat c_order:    [10 12 25 13 3 12 11 14 24 15 6 14] flat F_order:    [10 25 3 11 24 6 12 13 12 14 15 14]SolutionTo solve this, we will follow the steps given below −Define a dataframeApply df.values.ravel() function inside set an argument as order=’C’ and save it as C_order, C_order = df.values.ravel(order='C')Apply df.values.ravel() function inside set an argument as order=’F’ and save it as F_order, F_order = df.values.ravel(order='F')ExampleLet’s check the following code to get a better understanding ... Read More

Write a program in Python to print dataframe rows as orderDict with a list of tuple values

Vani Nalliappan
Updated on 25-Feb-2021 06:05:11

118 Views

Assume, you have a dataframe and the result for orderDict with list of tuples are −OrderedDict([('Index', 0), ('Name', 'Raj'), ('Age', 13), ('City', 'Chennai'), ('Mark', 80)]) OrderedDict([('Index', 1), ('Name', 'Ravi'), ('Age', 12), ('City', 'Delhi'), ('Mark', 90)]) OrderedDict([('Index', 2), ('Name', 'Ram'), ('Age', 13), ('City', 'Chennai'), ('Mark', 95)])SolutionTo solve this, we will follow the steps given below −Define a dataframeSet for loop to access all the rows using df.itertuples() function inside set name=’stud’for row in df.itertuples(name='stud')Convert all the rows to orderDict with list of tuples using rows._asdict() function and save it as dict_row. Finally print the values, dict_row = row._asdict() print(dict_row)ExampleLet’s check the ... Read More

Write a program in Python to caluculate the adjusted and non-adjusted EWM in a given dataframe

Vani Nalliappan
Updated on 25-Feb-2021 06:03:40

189 Views

Assume, you have a dataframe and the result for adjusted and non-adjusted EWM are −adjusted ewm:       Id       Age 0 1.000000 12.000000 1 1.750000 12.750000 2 2.615385 12.230769 3 2.615385 13.425000 4 4.670213 14.479339 non adjusted ewm:       Id       Age 0 1.000000 12.000000 1 1.666667 12.666667 2 2.555556 12.222222 3 2.555556 13.407407 4 4.650794 14.469136SolutionTo solve this, we will follow the steps given below −Define a dataframeCalculate adjusted ewm with delay 0.5 using df.ewm(com=0.5).mean().df.ewm(com=0.5).mean()Calculate non-adjusted ewm with delay 0.5 using df.ewm(com=0.5).mean().df.ewm(com=0.5, adjust=False).mean()Exampleimport numpy as np import pandas as pd df ... Read More

Write a Python code to fill all the missing values in a given dataframe

Vani Nalliappan
Updated on 25-Feb-2021 06:02:17

275 Views

SolutionTo solve this, we will follow the steps given below −Define a dataframeApply df.interpolate funtion inside method =’linear’, limit_direction =’forward’ and fill NaN limit = 2df.interpolate(method ='linear', limit_direction ='forward', limit = 2Exampleimport pandas as pd df = pd.DataFrame({"Id":[1, 2, 3, None, 5],                      "Age":[12, 12, 14, 13, None],                      "Mark":[80, 90, None, 95, 85],                   }) print("Dataframe is:",df) print("Interpolate missing values:") print(df.interpolate(method ='linear', limit_direction ='forward', limit = 2))OutputDataframe is:    Id     Age   Mark 0 1.0    12.0   80.0 1 2.0    12.0   90.0 2 3.0    14.0   NaN 3 NaN    13.0   95.0 4 5.0    NaN    85.0 Interpolate missing values:    Id     Age    Mark 0 1.0    12.0    80.0 1 2.0    12.0    90.0 2 3.0    14.0    92.5 3 4.0    13.0    95.0 4 5.0    13.0    85.0

Write a Python code to rename the given axis in a dataframe

Vani Nalliappan
Updated on 25-Feb-2021 06:00:35

278 Views

Assume, you have a dataframe and the result for renaming the axis is,Rename index: index    Id    Age    Mark    0    1.0    12.0   80.0    1    2.0    12.0   90.0    2    3.0    14.0   NaN    3    NaN    13.0   95.0    4    5.0    NaN    85.0SolutionTo solve this, we will follow the steps given below −Define a dataframeApply df.rename_axis() function inside axis name as ‘index’ and set axis=1df.rename_axis('index',axis=1)Exampleimport pandas as pd df = pd.DataFrame({"Id":[1, 2, 3, None, 5],                      "Age":[12, 12, 14, 13, None],                      "Mark":[80, 90, None, 95, 85],                   }) print("Dataframe is:",df) print("Rename index:") df = df.rename_axis('index',axis=1) print(df)OutputDataframe is:    Id    Age    Mark 0 1.0    12.0   80.0 1 2.0    12.0   90.0 2 3.0    14.0   NaN 3 NaN    13.0   95.0 4 5.0    NaN    85.0 Rename index: index    Id    Age    Mark    0    1.0    12.0   80.0    1    2.0    12.0   90.0    2    3.0    14.0   NaN    3    NaN    13.0   95.0    4    5.0    NaN    85.0

Write a Python code to find a cross tabulation of two dataframes

Vani Nalliappan
Updated on 25-Feb-2021 05:59:10

527 Views

Assume you have two dataframes and the result for cross-tabulation is,Age  12 13 14 Mark 80 90 85 Id 1    1  0  0 2    0  1  0 3    1  0  0 4    0  1  0 5    0  0  1SolutionTo solve this, we will follow the steps given below −Define two dataframesApply df.crosstab() function inside index as ‘Id’ and columns as ‘Age’ and ‘Mark’. It is defined below,pd.crosstab(index=df['Id'],columns=[df['Age'],df1['Mark']])Exampleimport pandas as pd df = pd.DataFrame({'Id':[1,2,3,4,5],'Age':[12,13,12,13,14]}) df1 = pd.DataFrame({'Mark':[80,90,80,90,85]}) print(pd.crosstab(index=df['Id'],columns=[df['Age'],df1['Mark']]))OutputAge  12 13 14 Mark 80 90 85 Id 1    1  0  0 2    0  1  0 3    1  0  0 4    0  1  0 5    0  0  1

Write a program in Python to print the length of elements in all column in a dataframe using applymap

Vani Nalliappan
Updated on 25-Feb-2021 05:58:11

376 Views

The result for the length of elements in all column in a dataframe is, Dataframe is:    Fruits    City 0 Apple    Shimla 1 Orange   Sydney 2 Mango    Lucknow 3 Kiwi    Wellington Length of the elements in all columns    Fruits City 0    5    6 1    6    6 2    5    7 3    4    10SolutionTo solve this, we will follow the steps given below −Define a dataframeUse df.applymap function inside lambda function to calculate the length of elements in all column asdf.applymap(lambda x:len(str(x)))ExampleLet’s check the following code to get ... Read More

Write a Python code to calculate percentage change between Id and Age columns of the top 2 and bottom 2 values

Vani Nalliappan
Updated on 25-Feb-2021 05:55:54

397 Views

Assume, you have dataframe and the result for percentage change between Id and Age columns top 2 and bottom 2 valueId and Age-top 2 values    Id Age 0 NaN NaN 1 1.0 0.0 Id and Age-bottom 2 values       Id      Age 3 0.000000 -0.071429 4 0.666667 0.000000SolutionTo solve this, we will follow the steps given below −Define a dataframeApply df[[‘Id’, ’Age’]].pct_change() inside slicing [0:2]df[['Id', 'Age']].pct_change()[0:2]Apply df[[‘Id’, ’Age’]].pct_change() inside slicing [-2:]df[['Id', 'Age']].pct_change()[0:2]ExampleLet’s check the following code to get a better understanding −import pandas as pd df = pd.DataFrame({"Id":[1, 2, 3, None, 5],         ... Read More

Write a Python program to perform table-wise pipe function in a dataframe

Vani Nalliappan
Updated on 25-Feb-2021 05:48:54

215 Views

Assume, you have a dataframe and the result for table-wise function is, Table wise function:    Id  Mark 0  6.0 85.0 1  7.0 95.0 2  8.0 75.0 3  9.0 90.0 4 10.0 95.0SolutionTo solve this, we will follow the steps given below −Define a dataframeCreate a user-defined function avg with two arguments and return the result as (a+b/2). It is defined below, def avg(a, b):    return (a+b/2)Apply pipe() function to perform table-wise function inside first value as avg() and the second argument as 10 to calculate the avg of all the dataframe values.df.pipe(avg, 10)ExampleLet’s check the following code to ... Read More

How to change the legend shape using ggplot2 in R?

Nizamuddin Siddiqui
Updated on 11-Feb-2021 12:17:30

1K+ Views

By default, the shape of legend is circular but we can change it by using the guides function of ggplot2 package. For example, if we have a data frame with two numerical columns say x and y, and one categorical column Group then the scatterplot between x and y for different color values of categories in categorical column Group having different shape of legends can be created by using the below command −ggplot(df, aes(x, y, color=Group))+geom_point()+guides(colour=guide_legend(override.aes=list(shape=0)))Here, we can change the shape argument value to any value between starting from 0 to 25.Consider the below data frame −Example Live DemoxRead More

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