Iteration is a general term for taking each item of something, one after another. Pandas DataFrame consists of rows and columns so, in order to iterate over dataframe, we have to iterate a dataframe like a dictionary. In a dictionary, we iterate over the keys of the object in the same way we have to iterate in dataframe.
In this article, we are using “nba.csv” file to download the CSV, click here.
In Pandas Dataframe we can iterate an element in two ways:
- Iterating over rows
- Iterating over columns
Iterating over rows :
In order to iterate over rows, we can use three function iteritems(), iterrows(), itertuples() . These three function will help in iteration over rows.
Iteration over rows using iterrows()
In order to iterate over rows, we apply a iterrows() function this function returns each index value along with a series containing the data in each row.
Code #1:
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) print(df) |
Now we apply iterrows() function in order to get a each element of rows.
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) # iterating over rows using iterrows() function for i, j in df.iterrows(): print(i, j) print() |
Output:
Code #2:
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") # for data visualization we filter first 3 datasetsdata.head(3) |
Now we apply a iterrows to get each element of rows in dataframe
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") for i, j in data.iterrows(): print(i, j) print() |
Output:
Iteration over rows using iteritems()
In order to iterate over rows, we use iteritems() function this function iterates over each column as key, value pair with the label as key, and column value as a Series object.
Code #1:
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) print(df) |
Now we apply a iteritems() function in order to retrieve an rows of dataframe.
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) # using iteritems() function to retrieve rowsfor key, value in df.iteritems(): print(key, value) print() |
Output:
Code #2:
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") # for data visualization we filter first 3 datasetsdata.head(3) |
Output:
Now we apply a iteritems() in order to retrieve rows from a dataframe
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") for key, value in data.iteritems(): print(key, value) print() |
Output:
Iteration over rows using itertuples()
In order to iterate over rows, we apply a function itertuples() this function return a tuple for each row in the DataFrame. The first element of the tuple will be the row’s corresponding index value, while the remaining values are the row values.
Code #1:
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) print(df) |
Now we apply a itertuples() function inorder to get tuple for each row
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from dictionary df = pd.DataFrame(dict) # using a itertuples() for i in df.itertuples(): print(i) |
Output:
Code #2:
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") # for data visualization we filter first 3 datasetsdata.head(3) |
Now we apply an itertuples() to get atuple of each rows
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") for i in data.itertuples(): print(i) |
Output:
Iterating over Columns :
In order to iterate over columns, we need to create a list of dataframe columns and then iterating through that list to pull out the dataframe columns.
Code #1:
Python3
# importing pandas as pdimport pandas as pd # dictionary of listsdict = {'name':["aparna", "pankaj", "sudhir", "Geeku"], 'degree': ["MBA", "BCA", "M.Tech", "MBA"], 'score':[90, 40, 80, 98]} # creating a dataframe from a dictionary df = pd.DataFrame(dict) print(df) |
Now we iterate through columns in order to iterate through columns we first create a list of dataframe columns and then iterate through list.
Python
# creating a list of dataframe columnscolumns = list(df) for i in columns: # printing the third element of the column print (df[i][2]) |
Output:
Code #2:
Python
# importing pandas module import pandas as pd # making data frame from csv file data = pd.read_csv("nba.csv") # for data visualization we filter first 3 datasets col = data.head(3) col |
Now we iterate over columns in CSV file in order to iterate over columns we create a list of dataframe columns and iterate over list
Python
# creating a list of dataframe columnsclmn = list(col) for i in clmn: # printing a third element of column print(col[i][2]) |
Output:
