Category: Python Answers

Sometimes, we want to fix UnicodeDecodeError when reading CSV file in Pandas with Python.

In this article, we’ll look at how to fix UnicodeDecodeError when reading CSV file in Pandas with Python.

How to fix UnicodeDecodeError when reading CSV file in Pandas with Python?

To fix UnicodeDecodeError when reading CSV file in Pandas with Python, we can use the read_csv method to read the CSV.

For instance, we write

import pandas as pd

df = pd.read_csv('file_name.csv', engine='python')

to call read_csv with the CSV file path and the engine argument set to 'python' to read it with native Python csv module into a data frame.

Conclusion

To fix UnicodeDecodeError when reading CSV file in Pandas with Python, we can use the read_csv method to read the CSV.

Sometimes, we want to use itertools.groupby() in Python.

In this article, we’ll look at how to use itertools.groupby() in Python.

How to use itertools.groupby() in Python?

To use itertools.groupby() in Python, we can use the groupby function with a list and a function to return the item to group by.

For instance, we write

from itertools import groupby

things = [('animal', 'bear'), ('animal', 'duck'), ('plant', 'cactus'),
          ('vehicle', 'speed boat'), ('vehicle', 'school bus')]

for (key, group) in groupby(things, lambda x: x[0]):
    for thing in group:
        print('A %s is a %s.' % (thing[1], key))
    print('')

to call groupby with the things list and a function that specifies that we group by the first item in each tuple.

Then a list with the tuples with the group key and the values of the group in a list returned.

Conclusion

To use itertools.groupby() in Python, we can use the groupby function with a list and a function to return the item to group by.

Sometimes, we want to zip lists in Python.

In this article, we’ll look at how to zip lists in Python.

How to zip lists in Python?

To zip lists in Python, we can call the zip method with multiple lists.

For instance, we write

a = b = c = range(20)

l = zip(a, b, c)

to call zip with lists a, b, and c.

Then we get a list with tuples with the items from each list at the position of the of the tuple in the returned list/

Conclusion

To zip lists in Python, we can call the zip method with multiple lists.

Sometimes, we want to write the Fibonacci Sequence with Python.

In this article, we’ll look at how to write the Fibonacci Sequence with Python.

How to write the Fibonacci Sequence with Python?

To write the Fibonacci Sequence with Python, we can create a generator function.

For instance, we write

def F():
    (a, b) = (0, 1)
    while True:
        yield a
        (a, b) = (b, a + b)

to create the F generator function.

In it, we assign a and b to their initial values.

And then in a while loop, we yield a and then we assign a and b to the next values in the sequence.

Conclusion

To write the Fibonacci Sequence with Python, we can create a generator function.

Sometimes, we want to make MySQL parameterized queries with Python.

In this article, we’ll look at how to make MySQL parameterized queries with Python.

How to make MySQL parameterized queries with Python?

To make MySQL parameterized queries with Python, we can call cursor’s execute method.

For instance, we write

c.execute("SELECT * FROM foo WHERE bar = %s AND baz = %s", (param1, param2))

to run a select query with a where clause with the MySQLdb library’s cursor’s execute method.

%s is a placeholder for the parameters that are stored in the tuple.

Conclusion

To make MySQL parameterized queries with Python, we can call cursor’s execute method.