Python for Data Analysis

import numpy as np import pandas as pd import matplotlib.pyplot as plt import seaborn as sns impo...

Data Structures Tuples A tuple is a fixed-length, immutable sequence. tup = (4, 5, 6) tup = 4, 5,...

dict Dictionaries are sometimes called hash maps or associative arrays. A dictionary stores a col...

Built-in Sequence Functions enumerate() enumerate returns a sequence of (i, value) in tuples. ind...

Basic Form [expression for value in collection if condition] result = [] for value in collection:...

Functions def func(x): return something Namespaces, Score, and Local Functions Functions can a...

Value Error float("1.2345") 1.2345 float("something") ValueError: could not convert string to flo...

open() path = 'examples/segismundo.txt' f = open(path, encoding = 'utf=8') for line in f: pri...

The default behavior for python files is text mode. This contrasts with binary mode, which you ca...

NumPy NumPy is short for Numerical Python. import numpy as np data = np.array([[1.5, -0.1, 3], [...

Pseudorandom Number Generation samples = np.random.standard_normal(size=(4,4)) samples array([[ ...

Array-Oriented Programming Suppose we want to evaluate a function sqrt(x^2 +y^2) across a regular...

Linear Algebra x = np.array([1, 2, 3], [4, 5, 6]) y = np.array([6, 23], [-1, 7], [8, 9]) np.dot(...

Series import numpy as np import pandas as pd # A Series is a one-dimensional array-like object ...

Reindexing Series reindex creates a new object with the values arranged to align with the new ind...

Arithmetic and Data Alignment s1 = pd.Series([7.3, -2.5, 3.4, 1.5], index=['a', 'c', 'd', 'e']) s...

Basic Functions df = pd.DataFrame([[1.4, np.nan], [7.1, -4.5], [np.nan, np.nan], [0.75, -1.3]], i...

Reading and Writing Data in Text Format Function Description read_csv csv read_clipboard...