Getting error str object is not callable in find by xpath

[sumandas89]

Here is my code segment -

for clk in range(1, int(lim)):
    for i in range(1, 101):
        tab_str = '//*[@id="tbody_other_search"]/tr['
        tab_str = tab_str + str(i) + ']/td[1]'
        print(tab_str)
        driver.find_element_by_xpath(tab_str).text()
        '''if int(num) % 100 == int(en_dig):
            print(num)'''
        driver.find_element_by_xpath('//*[@id="names_load_next"]/a/i').click()
    WebDriverWait(driver,5)

I confirmed that the correct xpath is generated in tab_str by the printing the xpath but getting the error for the line -

driver.find_element_by_xpath(tab_str).text()

and here is the error -

Error:
driver.find_element_by_xpath(tab_str).text()
TypeError: 'str' object is not callable

What is the reason of error? please share with me.